Ingersoll Rand® has released the 2135QTL-2 1/2" Torque Limited Impact Wrench. The 2135QTL-2 is Ingersoll Rand’s fastest and quietest torque-limiting impact wrench. Ingersoll Rand quiet technology noticeably reduces noise levels in the shop. The tool restricts forward torque from 55 to 75 foot-pounds, reducing the chance of damaging wheels without sacrificing a single foot-pound of reverse torque.
The 2135QTL-2 is the ultimate torque wrench counterpart. It delivers 780 foot-pounds of max reverse torque to remove stubborn lug nuts quickly and reaches target torque in two to three seconds. It weighs just 4.3 pounds to reduce fatigue with repeated use. The 2" anvil provides better access to recessed lug nuts, ideal for tire shops and service centers.
The motor and impact mechanism are optimized for better durability. The motor air flow controls the torque instead of the mechanism, making it three times more durable than previous torque limiting impacts.
The 2135QTL-2 also includes the following features:
Tough, steel-lined aluminum hammer case for increased durability
Chemical resistant composite housing to withstand harsh working conditions and shop fluids
Swivel hose connection to prevent tangling so technicians can move freely around the shop
On April 29, 2019, Ranger Design will be launching the next generation of our drop-down ladder rack, the Max Rack 2.0! Tough, safe and simple, this rack is a fit for extreme use on the jobsite.
Built as a solution for all high roof cargo vans, the Max Rack 2.0 allows tradesmen easy access to their ladders with the least amount of effort. The loading and unloading process is a smooth, single stage operation that drops the ladder down to the right height, quickly and efficiently. By reducing the sweep angle of the rack handle by 45 degrees, it’s now even easier for tradesmen to operate the rack from the ground.
In keeping with our high safety standards, there’s no need to stand below the ladder while it lowers thanks to our industry exclusive single stage drop. Bi-directional dampers in the rack’s mechanism ensure a smooth operation both to raise the ladder and to lower it. Another enhanced safety feature of the Max Rack 2.0 is its reduced profile, now sitting 3” lower to diminish chances of catching any low hanging objects such as drive-thru signs or tree branches.
Made from military grade aluminum to eliminate any opportunity of rust or corrosion, the Max Rack 2.0 is designed for carrying extension ladders and step ladders. With a new Max Rack 2.0 proudly installed on their vehicle, contractors can be sure that their life on the jobsite will only improve!
About Ranger Design
Ranger Design is known as an innovative designer and manufacturer of specialized van shelving, van racking, ladder racks, partitions and storage systems for commercial vehicles. With a network of over 300 distributors across North America, Ranger Design is dedicated to providing products that offer the highest degree of quality, an industry leading warranty, and world class customer service.
Red Line Synthetic Oil, a leading manufacturer of performance lubricants, offers superior brake performance with its RL-600 Full Synthetic Brake Fluid. Formulated using the highest-quality esters that Red Line is known for throughout its line of high-performance lubricants, RL-600 is ready for use in road vehicles, race cars, off-roaders and motorcycles.
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RL-600 is a DOT 4 brake fluid engineered using a strict combination of Borate Esters and Glycol Ethers, in addition to specific moisture and corrosion inhibitors, for exceptional performance under any conditions. Brake fluids of all kinds are subject to moisture absorption throughout their lifecycles and that moisture can reduce the fluid’s wet boiling point, lowering its effectiveness. Red Line’s RL-600 combats this problem with its use of components which reduce moisture absorption.
Repeated hard braking, such as in race conditions, generates a great amount of heat and places the brake fluid under immense pressure. Both conditions can be detrimental to the operation of the brakes, as the brake fluid can boil and become compressible, leading to vapor lock and brake fade. RL-600 is developed to resist these issues and maintain lubricity, compressibility and viscosity under the most extreme conditions at the race track or on the street. The fluid has a dry boiling point of 604 degrees Fahrenheit and wet boiling point of 400 degrees Fahrenheit, far greater than the minimum requirement for DOT 4 brake fluids. Additionally, Red Line’s RL-600 can blend with DOT 3, DOT 4 and DOT 5.1 brake fluids, delivering more responsive and consistent pedal feel.
“It doesn’t matter if you’re on the race track or driving home from the grocery store, the last thing any driver wants is an inadequate or unreliable braking system,” said Michael Andrew at Red Line Synthetic Oil. “Red Line’s RL-600 continues the proud Red Line tradition of offering exceptional and reliable products that perform under pressure.”
For more information on Red Line Synthetic Oil, please visit www.redlineoil.com or follow Red Line Synthetic Oil on Instagram, Facebook or LinkedIn.
You know you need to look up TSBs when you’re creating your diagnostic game plan, but do you really understand the background of the TSB?
If you aren’t fully sure, you’re not alone. Many technicians know they’re supposed to use the important tool, but might not fully understand why they are issued or how they differ from other information about vehicle repair.
Technical Service Bulletins– the TSB – is a type of service information an original equipment manufacturer (OEM) releases based on service issues it sees in the field. Industry expert Gary Hixson, a senior market manager with Mitchell 1, returns in “Finding and Using the Right TSB” a new video to outline a number items technicians need to know about TSBs.
Starting with four reasons an OEM might release a TSB, Hixon steps through what a TSB is, and isn’t, explaining the differences between TSBs, recalls and campaigns. Each serves its own purposes to help technicians diagnose and repair known issues with the vehicle.
Watch “Finding and Using the Right TSB”and learn more about the history of TSBs, what to look for when you pull on in a diagnostic search and where to find complete TSBs and other information for your repairs.
ZF Technical Training has announced the 2019 schedule for full day training classes, in which technicians across the country can take advantage of a hands-on learning experience with ZF Aftermarket’s technical trainers. Topics will include 6HP and 8HP transmission operations and diagnostics and modern chassis technologies.
Full day technical training classes from ZF Aftermarket are slated to kick off next week at ZF Aftermarket’s Vernon Hills, IL location. This year’s training courses will cover modern chassis technologies as well as diagnostics for 6HP and 8HP transmissions. ZF technical trainers have designed engaging, customized programs that bring ZF’s OE expertise into the hands of technicians in the automotive aftermarket.
“Transmissions and chassis technologies are essential topics for automotive technicians and being tuned into the latest changes is vital for success,” said Dirk Fuchs, ZF Aftermarket, Technical Training Manager.
“Our mission is to support independent aftermarket shops across the country; to that end, we take our training courses from coast to coast, creating opportunities for technicians to grow their knowledge and improve their skills in this industry.”
Class Information
The current ZF Technical Training course schedule is as follows:
8HP Transmission Diagnostics & Overhaul
March 30th, 2019 at the ZF location in Vernon Hills, IL
June 22nd, 2019 in Los Angeles, CA
Spanish class: June 22nd, 2019 in Los Angeles, CA
6HP Transmission Diagnostics & Overhaul
September 14th, 2019 in Toronto, ON
Modern Chassis Technologies
April 27th, 2019 in Dallas, TX
August 10th, 2019 in NYC/Philadelphia area
October 12th, 2019 in Detroit, MI
In each class, attendees receive an in-depth, full day training with an ASE-certified ZF technical trainer. Trainers will review essential information and address common concerns of each topic and give technicians the confidence and strategies needed to better meet the challenges of the constantly changing automotive industry.
Expert Education
ZF Aftermarket Technical Training equips technicians, industry students, and automotive professionals with in-depth knowledge and training on automotive technology. Our trainers aim to provide the expertise necessary to diagnose, repair, and service most automotive products. With several decades of experience in the field between them, ZF technical trainers provide job-applicable industry knowledge for the automotive aftermarket.
Registration for 2019 full-day hosted technical trainings is now open. Classes are limited to 25 people; if a class is full, registrants may request to be placed on a waiting list for a second class. To register, class information or for additional resources on ZF Aftermarket Technical Training, please visit www.aftermarket.zf.com/us/trainings.
Red Line Synthetic Oil, a leader in the performance lubricants industry, today announced a partnership with legendary motorsports training academy, the Skip Barber Racing School. Going forward, Red Line products will be the exclusive supplier of lubricants used by the school. The company will also provide technical support, ensuring that the Skip Barber Racing School is outfitted with the highest quality products available at all times.
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As the official lubricant supplier of the Skip Barber Racing School, Red Line will outfit each Mustang GT in Skip Barber’s fleet with motor oil, transmission fluid, gear oil and brake fluid to ensure the cars are fully equipped to handle the demanding race track conditions, day in and day out. Each vehicle will see over 150 track days per year, so high-quality lubricants are essential. To signify the partnership, Skip Barber’s Mustang GTs will prominently feature Red Line’s logo on the vehicles.
“We are thrilled to team up with the Skip Barber Racing School, one of the most respected names in motorsports instruction and training,” said Michael Andrew at Red Line Synthetic Oil. “Skip Barber has carved a reputation as a premiere race car driving school and is an ideal partner to showcase the superior quality and longevity of Red Line products crafted from Red Line’s own racing heritage.”
“Our cars are some of the hardest working vehicles out there, eclipsing 20,000 track miles per year, and because of this they require the best lubricants and additives to keep them running at their peak,” said Anthony DeMonte, CEO at the Skip Barber Racing School. “Red Line Synthetic Oil’s dedication to motorsports and quality aligns with Skip Barber’s mission to provide the very best instruction to anyone looking to learn and improve their driving.”
Red Line Synthetic Oil and the Skip Barber Racing School were founded in the 1970s and quickly became renowned leaders in their respective industries. Both companies have demonstrated an unwavering commitment to the world of motorsports. Skip Barber graduates have distinguished themselves with podium appearances in all the major, international series including Formula 1, NASCAR, IMSA, Blancpain GT World Challenge America, CanAm and IndyCar. Similarly, Red Line’s products have been used by championship winning teams to give them the utmost edge over the competition. Through this partnership, the two businesses will continue their mandate of excellence in motorsports in a new and exciting way.
For more information on Red Line Synthetic Oil, please visit www.redlineoil.com or follow Red Line Synthetic Oil on Instagram, Facebook or LinkedIn.
Do you own a timing light? When was the last time you used it? Old guys like me know what it is, but do younger technicians have a clue? To be fair, the answers to these questions vary based on geographic location. I am in the Chicago area and I cannot remember the last time I used a timing light. Salted roads, rust, emissions testing and “cash for clunkers” eliminated 99 percent of the vehicles that required ignition timing adjustments in my area. I own a fancy timing light but it probably has a thick layer of dust on it… if I can even find it. If I lived in an area like Phoenix or San Diego, this story might be completely different. Environmental/geographic issues such as this can often result in a 2018 vehicle in one bay of a shop while a 1976 vehicle could be right next to it. Not in Chicago! I rarely see something older than 1996, but I still own a blue wrench just in case. Regardless, ignition timing is a very important aspect of engine performance.
The demise of timing marks
Today’s engine applications usually do not offer technicians a method of checking ignition timing because it is no longer adjustable. Most frequently there are no timing marks on the crankshaft pulley and no spark plug wires to connect our timing lights to if we even wanted to perform such a task. To muddy the waters even further, manufacturers no longer provide base ignition timing specifications. Does this mean that ignition timing is any less important? Of course not. My point: ignition timing can be incorrect, even though it is not adjustable by a technician, and subsequently cause driveability issues.
Figure 1 - A distributor, or an “octopus,” on a 1970 Challenger R/T.
For those of you who are green, or entry level technicians, let me paint this picture. There used to be a device on the engine that looked like an octopus (Figure 1). This “octopus” was actually called the distributor. It had ignition cables that plugged into the spark plug for each cylinder on the engine and often had an additional wire that connected to a single ignition coil. Yes, believe it or not, only one ignition coil. The octopus’ job was to distribute spark at the appropriate time to each individual cylinder. In order to do so the distributor, or the head of the octopus, needed to be installed correctly. It could be turned, in one direction or another, to establish base ignition timing. From there the engine computer would take over and advance or retard ignition timing, or when the spark fired, based on operating conditions at that moment.
A side note that should be addressed: For a few years in the mid-1990s and early 2000s, distributors existed on vehicles, but ignition timing adjustments were not possible. Even though it was possible to turn the distributor, this only effected camshaft sensor timing. This adjustment affected injection timing but not ignition timing. Ignition timing was now based on the crankshaft position sensor input to the PCM. An example of this would be a General Motors 5.7- and 5.0-liter engine as recently as the 2000 model year and the General Motors 4.3-liter engine all the way up to the 2004 model year.
With the introduction of DIS (Direct Ignition Systems) in the early 1980s and COP (Coil over Plug) ignition systems shortly after that, the octopus became obsolete. As a result, ignition timing adjustments became obsolete as well. These changes did not mean that ignition timing was any less important, it just became a non-adjustable part of the technician’s service procedure because mechanical components were eliminated and computerized ignition controls took charge of all ignition functions.
Gone but not forgotten
Now that the history lesson is complete, we come to how ignition timing is controlled on a modern vehicle. Ignition timing on almost all modern vehicles is based on the crankshaft position sensor input. The aspects for the operation of a four-stroke engine are still the same as it always has been, including ignition timing, and service information has kept up pertaining to most areas as engines have changed and advanced. However, service information lacks when it comes to the important variable of ignition timing. Because ignition timing is non-adjustable on modern vehicles the engineers designing the vehicles, and the individuals writing the service information, do not give us technicians all of the information we may need because ignition timing is something “we should no longer mess with.” Allow me to share a story that illustrates the need for ignition timing specifications.
An early 2000s Ford with a 4.2-liter V-6 engine is in the shop for a low-power issue. The shop had already used the usual shotgun approach and replaced the fuel pump, fuel filter, mass airflow sensor, entire exhaust system (everything except the exhaust manifolds), camshaft position sensor, spark plugs, ignition wires and coil pack. In a very inefficient and costly way, the shop covered most of the bases for a low power issue. Upon my arrival at the shop, a test drive of the vehicle confirmed that the low power issue remained. A double check of the parts/components that were replaced was performed and no faults were found. What was missed? Was ignition timing checked? Us old guys know retarded ignition timing can cause a very similar feeling drivability result but, as stated before, there were no timing marks or specifications for the checking of ignition timing. What do we do next?
Figure 2 - A worn keyway allowed a skewed CKP signal that results in retarded ignition timing.
A quick test of ignition timing, using some modern techniques (to be addressed shortly,) revealed that the ignition timing was in fact retarded. Because the ignition timing is based on the crankshaft position sensor signal the CKP reluctor was the next thing on the list to check. In this case the CKP reluctor was mounted on the crankshaft pulley. Removing the crankshaft pulley revealed a worn keyway that allowed the crankshaft pulley to shift (Figure 2). This shift resulted in a CKP signal that was late. The late CKP input signal to the PCM resulted in a late, or retarded, ignition timing trigger signal to the ignition coils. The only thing that was required to resolve the low power issue on the vehicle in question was a crankshaft pulley. The new pulley resulted in an accurate CKP signal to the PCM and consequently a correct ignition timing command.
My point of this whole story is that technicians nowadays, seasoned techs and green techs alike, overlook ignition timing because it is “non-adjustable.” Technically it is not adjustable, but it can change… if something is broken.
Checking ignition timing without a timing light
So how do we check ignition timing you may ask? A few paragraphs ago I referred to a “quick test” to check ignition timing on a modern vehicle. With the appropriate equipment, and knowledge of how engines work, this is actually an easy task. There are two methods that I am aware of that can be used to check ignition timing. Both of these tests require an oscilloscope. In addition, a high current probe and/or a pressure transducer will be needed. The current probe or the pressure transducer will provide a top dead center reference. Another channel of the scope will be used as an ignition reference and can be accomplished in a variety of ways depending on vehicle application and available scope probes. The first technique is a “ballpark” test and the second technique is much more accurate than the first.
Method #1: Relative compression in relation to sync
Relative compression involves connecting a current probe around a battery cable, disabling the fuel system to force a crank no start condition and using some type of ignition sync. The engine is then cranked over and the starter motor’s current peaks can be observed. The current peaks equate to the higher effort required by the starter motor to compress the contents of each cylinder. Equal current peaks indicate that all cylinders have equal compression. For our discussion today, the ignition sync should fall near the apex of one of current peaks in the capture. This technique is not exact, but can give us a pretty good idea if ignition timing is close. Think about it — during cranking, most engine applications use base ignition timing. If we use what we have learned from older vehicles, calling on you seasoned technicians, the base timing should be (most likely) somewhere between O degrees to 10 degrees BTDC (Before Top Dead Center). This means that the ignition sync should occur very close to one of the current peaks or slightly to the left of the relative capture. If the ignition sync falls too far to the right of the current peak then the ignition timing is retarded. Conversely, if it falls too far to the left, the ignition timing is advanced.
Figure 3 - The ignition sync falls well to the right indicating retarded ignition timing.
The following relative compression capture (Figure 3) is from a 2002 Ford Mustang with a 3.8 liter engine. The vehicle barely ran and the relative compression capture explains why — Ignition timing is severely retarded.
Fugure 4 - A broken crankshaft balancer caused the CKP reluctor to shift
Further investigation, focusing on the crankshaft position sensor, revealed a damaged (Figure 4) crankshaft balancer.
Figure 5 - A relative compression capture with slightly questionable ignition timing.
Another example could be this next capture of another Ford vehicle. Figure 5 illustrates ignition timing that is questionable. The ignition firing (purple) appears to be near top dead center or even a bit to the right, or retarded. In this case ignition timing is suspect and more testing should be performed.
Method #2: In-cylinder compression in relation to sync
In-cylinder testing is a much more accurate way to measure ignition timing and would be the next diagnostic step in the case of the vehicle used in Figure 5. This technique will still require an ignition sync, but will also requires the use of a pressure transducer to establish TDC (Top Dead Center) and 720° of crankshaft rotation. Unlike the relative compression test, this test can be done during engine cranking or while the engine is running. In addition, very accurate ignition timing measurements can be made.
To facilitate this test a spark plug is removed and a pressure transducer is installed in its place. The engine is then cranked over or started. The highest point in the pressure capture is top dead center. The ignition sync can then be compared to actual top dead center and, if desired, can be measured with more accuracy.
Figure 6 - Ignition timing while running should be advanced. This capture shows near top dead center.
Figure 6 is an in-cylinder capture from a different vehicle. The vehicle is running at idle and it is obvious that the spark firing event occurs almost exactly at top dead center.
The timing of this ignition event should raise a question: When a vehicle is running shouldn’t the ignition timing be advanced? The answer is yes and the conclusion is that something is broken.
Measuring ignition timing
If you own a PicoScope, measuring timing of an event is relatively easy. The rulers can be used to mark two consecutive top dead center pressure events to give the scope a 720° reference. Then a cursor can be dragged to line up with the timing event that you desire to measure. A box will appear at the top of the scope screen and the difference in degrees will be displayed.
Figure 7 - A 720 degree event is measured to be 527.2 millisecond
If you are using a scope that does not offer this option, such as a Snap-On product, this task can still be performed relatively easily with a little bit of math. First, use your cursors to mark a 720° event from top dead center to top dead center. The scope will display the amount of time that the 720° event took (Figure 7). In this case that measurement is 527.2 milliseconds. Second, divide the amount of time of the event displayed on the scope by 720. This will tell us how much time each degree of crankshaft rotation is responsible for. In our example, 527.2 milliseconds divided by 720 degrees equals .73 milliseconds per crankshaft degree. Third, leave the first cursor at top dead center and move the second cursor to the timing event you wish to measure (Figure 8). A new time measurement will be displayed on the scope screen. In our case that number is 29.46 milliseconds. Finally, divide this new time measurement by the number obtained during the second step. In our example, 29.46 milliseconds divided by .73 milliseconds equals 40 degrees. This number represents the amount of timing advance, or retard, for the given capture. In this case the ignition timing is retarded 40 degrees. Remember, no matter which tool or method you are using, if the event occurs to the right of top dead center this indicates a retarded timing event and to the left of top dead center would indicate an advanced event.
Figure 8 - The ignition firing event is measured and occurs at 29.46 milliseconds after top dead cente
Summary
Ignition timing is just as important as it always has been for the proper operation of a spark ignition internal combustion engine even though technological advancements have eliminated the technician’s ability to adjust, or even check, base ignition timing. The obsolescence of timing lights, timing marks and timing adjustments have resulted in an industry mentality that tends to forget this important issue.
Technically, ignition timing should never have to be checked on a modern vehicle. The engineers, as a result, did not give us the ability to do so. However, in the engineers’ defense, every potential failure cannot be anticipated. Yet components do break and we technicians have to adjust our diagnostics to these unforeseen situations. Who knows, maybe some day we will see the return of timing marks on a crank pulley for the purpose of diagnostics. I doubt it. Maybe we can get a diagnostic trouble chart that actually leads us to a vehicle fault in a timely and accurate manner. There is a saying that has something to do with which hand fills up faster: “Wish in one hand and…"
Way back in the day, vehicle owners had "tune-ups" performed on their cars every year, or every 15,000 miles or so. The reason was simple. Most of the engine management systems were mechanical and wore over time. The contact breaker points in the ignition system, for example, had to be cleaned (or replaced) and adjusted to keep ignition timing in specification. The idle mixture and choke linkages on the carburetors of the day needed tweaking once a year to maintain fuel efficiency and ease of starting. Today, though, these systems are electronic and computer controlled - never requiring adjustment or replacement.
So if these services are no longer needed, is a tune-up still a valid service to offer?
Tune-up defined
One definition of the term is "a general adjustment to ensure operation at peak efficiency.” Some sources add "a process in which small changes are made to something (such as an engine) in order to make it work better." By either definition, using the term "tune-up" on your menu board may still be valid — though the processes included in that labor operation may have to be modified to reflect the needs of cars today.
This is one of the more severe filters I've seen. But who's going to check it, if not you?
For example, we aren't adjusting points or timing anymore, but we still service ignition spark plugs. Most cars don't require valve adjustment but some do and including that operation in your offering would meet the definition of making a "general adjustment," wouldn't it? And how about the idea of removing carbon build-up, especially on those models we know are prone to them? Isn't that making a "change" that makes it work better? Based on these few examples, the term is still valid. But is it practical?
There, I think, the answer is a solid "No."
And for a few reasons. First is the impracticality of offering a general service item to fit a variety of applications. You just can't break it down like we used to and offer a 4-cylinder, 6-cylinder or 8-cylinder job. Second is the connotation that surrounds the word. Many customers still come in requested a tune-up, thinking that it will cure whatever ails their car's driveability.
So what do you offer?
The 30-60-90 menu board
An option that gained popularity a few decades ago and still graces the menu boards of some shops is the concept of the "routine service" based on 30,000 mile intervals. Not a bad idea, for the most part, because these services often addressed the maintenance needs of the entire vehicle and not just the engine. Many of those offering these menu items included, at the least, transmission and coolant fluid exchanges as integrated parts of the service.
But this, too, is getting to be a bit archaic. Maintenance needs still exist, though maybe not at the same levels as they used to. Better yet is the idea of setting up a routine maintenance plan for your customer based on the OEM’s maintenance recommendations. These schedules can be found in both OE and aftermarket service information sources. Since they are included in the customer’s owner’s manual, there is additional justification for your recommendations.
Spark plug service is still a normal offering but alone, doesn't make a "tune-up."
If you’re familiar with the OE schedules, you know most list two: one for “normal” service and one for “severe” service. So which do you recommend? To quote one OEM’s criterion:
Follow the severe conditions maintenance schedule if you drive your vehicle MAINLY under one or more of the following conditions:
driving less than 5 miles per trip OR less than 10 miles per trip in freezing temperatures
driving in extremely hot (over 90 degrees F) conditions
extensive idling or long periods of stop-and-go driving, such as a taxi or commercial vehicle
trailer towing, driving with a roof rack, or driving in mountainous conditions
driving on muddy, dusty, or de-iced roads
I don’t know about you, but my primary driving habits meet at least one! Recommend using the “severe” schedule to your customers to help them “ensure operation at peak efficiency.”
What if it's not on the schedule?
One maintenance item that comes to mind that is not on the service schedule of some OEMs is the need for brake fluid replacement. It seems that no domestic maker lists a recommended service interval. Europeans, and some Asians, however, do specify service intervals for their vehicles. What should you do?
We all know that brake fluid is hygroscopic, meaning it absorbs moisture. As the moisture content builds, the boiling point of the fluid drops. This can reach a point where hard braking causes the water in the system to boil out, resulting in a loss of (or spongy) pedal. Moisture in the system was a problem back in the day but, like every other system now, they are sealed much better and the opportunities for water to enter more often come from the use of already contaminated fluid. Still an important check, but the absence of moisture does not mean the fluid is healthy.
The best way to test brake fluid (and coolant) is to measure the acidity, or pH, of the fluid.
As further studies were done, experts began recommending measuring the copper content of the fluid. This can be done by the use of specialty test strips and provides an indication of the condition of the anti-corrosion additives used in the fluid. But, according to the folks who make the test strips, copper content becomes almost useless if the brake system has had the fluid exchanged already. Why? The copper comes from the copper brazing in the brake lines and if the system has already had the fluid exchanged, those particles are flushed out. Now, the focus is on measuring the acidity, or pH, of brake fluid as a key indicator. A highly acidic fluid is another indication of additive depletion and reason for a fluid service.
Another vehicle fluid that shouldn't become too acidic is the coolant. It, too, uses a type-specific additive package that is charged with keeping the coolant and the cooling system components healthy. Unlike the brake system, however, the cooling system is much more open to outside attack (from poor electrical grounds, improper water selection and undiagnosed head gasket leaks, to name a few enemies) — and premature failure of the fluid results. Here, you may find yourself testing and recommending a fluid exchange to a customer who just had one recently completed. Just be sure to correct the cause of the early coolant demise at the same time.
Assessing the condition of the engine oil is generally not an issue. Most consumers understand the need to change that one routinely, even if it's only because it's become ingrained in our society's psyche. What you may consider offering, though, is from a lesson learned from our Class 8 cousins — have the oil analyzed by a lab. These analyses can often help dial in a customer's individual maintenance schedule as well as detecting trace elements that may point to undiagnosed failures, or pending failures. For example, traces of coolant in the oil could indicate a slight leak in a head gasket that is causing no other problems than contamination of the coolant as I shared above. But, if left unchecked, it could lead to much worse.
Recommend fluid services when the fluid service is required. Sometimes, that's before or after what the owner's manual might say.
Similar is the analysis of the vehicle's transmission fluid, even before it's changed. Some fluids are labeled as "lifetime" but we technicians treat that term with some pessimism. The fluid, if left alone and uncontaminated, may just last the lifetime of the vehicle but we can't help but wonder, what if? An analysis will provide data on trace elements that will help you gauge the condition of the fluid as well as catch any internal issues before they become major problems.
Agreed, these are all more involved and higher scale services than what we may be used to offering our clients. But the vehicles they are driving are also on a much higher scale, aren't they? The cost of ownership is rising, the cost of repair and service is right behind it and helping your customer control that cost as much as possible will only help you earn, and keep, his business.
Anyone familiar with the internal combustion engine understands that these devices produce carbon. This is a result of using hydrocarbon fuel stocks and lubrication oil within the engine. There are many different types of fuels currently used in the U.S. and aboard; however, the two primary fuel stocks used in the U.S. for on-highway transportation are gasoline and diesel. Either of these fuel stocks will produce carbon as a result of the combustion process within the cylinder.
The fuel is comprised of chains, rings and branches of hydrogen and carbon. When fuel reacts with oxygen during the combustion process carbon and hydrogen atoms from the fuel disassociate from one another and form new chemical bonds with oxygen. Hydrogen atoms react with oxygen to form dihydrogen monoxide (H2O — water), and carbon atoms react with other oxygen to form carbon dioxide (CO2). If the amount of hydrogen, carbon and oxygen atoms are not in the exact ratio to complete these reactions then some hydrocarbons are not completely combusted. The hydrocarbons that do not combust or do not burn completely either stay as hydrocarbons or form other chemical compounds such as carbon monoxide (CO).
When an organic compound, such as a hydrocarbon-based fuel, has a combustion reaction it produces heat. If there is a lack of oxygen during the burning of the fuel then pyrolysis occurs, which is a type of thermal decomposition that occurs in organic materials exposed to high temperatures. Pyrolysis of organic substances, such as fuel and oils, produces gas and liquid products but also a solid residue rich in carbon. Heavy pyrolysis leaves mostly carbon as a residue and is referred to as carbonization. Pyrolysis can occur rapidly or slowly depending on the temperature. An example of slow pyrolysis is the formation of carbon deposits within the induction system of the engine. Lubricating oils and fuels accumulate in the intake system and, when exposed to heat over a period of time, pyrolysis bakes off some of these oils and fuels as light chemicals and leaves heaver chemicals. Over time this becomes heavy carbonization (carbon deposits).
Same but different
It is important to understand that the carbon produced within an engine is not all the same. The carbon in the combustion chamber is produced under high heat and high pressure. Due to the conditions within the combustion chamber the carbon produced is denser and has low porosity; additionally, the carbon thickness is usually low. The carbon that is produced within the induction system is created under very different conditions than the combustion chamber deposits. The carbon in the intake is produced under low heat and low pressure. Due to the conditions within the induction system the carbon produced has high porosity; additionally, the carbon thickness can be quite high. Thus, due to the conditions that they were produced under, these are two different carbon types.
Figure 1
Another way to produce different carbon types within the engine is the use of different fuel delivery systems. When fueling the engine with a carburetor or port fuel injection the fuel is delivered into the intake manifold of the engine, as illustrated in Figure 1. Thus, the carbon within the intake port area is constantly washed by gasoline. As you already know, gasoline is a very good cleaner and can wash oils and sludge off of parts. Gasoline can remove some of the carbon accumulation from the induction port as well. The gasoline being in contact with the carbon deposit as it is forming will also change the configuration of carbon bonds in the induction system’s carbon deposit.
Figure 2
On modern engines that incorporate the method of Gasoline Direct Injection (GDI), the fuel is delivered directly into the combustion chamber as illustrated in Figure 2. Therefore, there is no fuel available to wash the carbon deposit in the intake manifold, as occurs with the port fuel injection method. This creates a problem in that the carbon deposits will build without opposition. Additionally, the lack of gasoline within the induction system can create a carbon bond configuration that is again quite different. Under these conditions the carbon deposits can become quite large and create drivability problems. On some GDI engines these carbon accumulations that create drivability problems can occur in as little as 15,000 miles. The very design of the GDI engine leads itself to carbon deposit in the induction system. No GDI engine is immune from these inherent carbon deposits.
Figure 3
Some carbon deposits within the GDI intake port area can be as great as ¼- to ½-inch thick as shown in Figure 3. These heavy carbon deposits can cause problems such as; misfiring cylinder(s), hesitation during throttling, low power, rough idle, surging, pinging, fuel trim adaptions, high tailpipe emissions, MAF range or performance DTC and MAP range or performance DTC.
The effects of carbon build up
In order to know if there are carbon deposits in the induction system of the engine you are working on, visual inspection using a borescope is the preferred method. One can find an entry point through a vacuum port or by removing a sensor such as the MAP sensor, or IAT sensor. If these will not provide access, with the ignition key off, the throttle plate can be opened and the borescope can be fed through this opening.
The carbon accumulations within the intake port area will create turbulent airflow. Additionally, if the carbon deposits are not deposited uniformly, they can create additional turbulent airflow. It is important to understand that these carbon deposits do not need to be heavy in order to create many of these problems. On the GDI engine small carbon accumulations in the intake port area can cause drivability problems. Every racer that has ported heads on a flow bench will attest to the fact that very small changes made within the intake runner and intake port area will create flow differences; both good and bad. These uneven intake carbon accumulations rob power, torque and fuel economy.
The turbulent air caused by carbon deposits is especially harmful in the GDI engine. This can best be understood by analyzing both the port fuel injection and GDI methods. When the port fuel injection method is utilized the fuel is injected directly at the back of the closed intake valve. The intake valve being the hottest part of the intake port, at 400°F to 800°F, will help vaporize some of the fuel so it can burn during the combustion process. Once the fuel is injected the intake valve opens, allowing the Air-Fuel mixture to be mixed by the swirling air movement past the valve. Additionally, the piston’s upward movement during the compression stroke forces this mixture together further mixing the air-fuel charge.
What this accomplishes is a very well mixed air-fuel charge that is very close to a truly homogenous mixture, which means that the charge mixture (air and fuel) has a uniform composition throughout the cylinder. When the spark occurs, it takes the fuel beyond its auto-ignition point and the flame front propagates across the combustion chamber. If the air-fuel charge is unevenly mixed, the propagation of the flame front will be impeded. This will cause incomplete combustion of the charge. If the air-fuel charge is homogenous this flame front will propagate through the combustion chamber allowing complete combustion to occur.
Figure 4
In the GDI engine the fuel is directly injected into the cylinder. With this type of fuel injection there is no ability to premix the Air-Fuel charge prior to the intake valve opening. Additionally, the swirl or tumble effect as the intake valve opens cannot be utilized. Therefore, the airflow into the cylinder is critical. This airflow must enter the cylinder and swirl correctly in order to catch the aerosolized fuel and completely mix these two components together, as illustrated in Figure 4. Time is another constraint in the mixing of these two components together. There is very little time for the air charge to mix with the fuel delivery, so the conditions must be correct in order to get this event to occur properly.
If the GDI engine’s intake port area, and/or intake valve becomes carbonized with deposits to the point where it effects this incoming airflow, then the proper mixing of the air and fuel cannot take place. If this air charge is not properly formed the fuel mixing event will not create a good homogenous mixture which will lead to incomplete combustion.
Since the internal combustion engine is a heat engine, the fundamental operation of the device is the production and use of heat that can then be converted to mechanical energy. In these engines everything that is done prior to the combustion of the fuel type is to set up the air-fuel in the cylinder so the charge can be ignited, burned, and combusted. In the spark ignition gasoline engine, a well-mixed air-fuel blend will have a greater chemical conversion rate during the combustion process. If this mixture is not a homogenous charge the maximum chemical potential will not be converted into thermal energy and hence mechanical energy.
Dealing with carbon build up
Therefore, it is imperative to keep carbon accumulations to a minimum in these GDI engines. But how can we accomplish this? Obviously, disassembly of the engine and hand cleaning is one possibility. In order to accomplish this the intake manifold will need to be remove from the head. Now that access to the intake port area is provided, rotate the engine until both valves for the port to be cleaned are closed. Now, using a plastic scraper carefully hand scrape the large carbon deposits from the port area. Do not put force behind the scraper. You are just removing the main body of carbon so the media blaster can be more effective. Once you are done use an air nozzle to blow out any remaining carbon from the port. Next, use a walnut shell blaster to clean the remaining carbon from the port area. Clean each cylinder’s intake port area while the intake is off. Additionally, while the intake manifold is off don’t forget to clean the intake runners. GDI engines can have large carbon accumulations within the manifold.
New media and or walnut shell blasters are available and provide good results. However, these solutions are time intensive and expensive. Due to these limitations this can only been done when the engine has large carbon accumulations that create severe drivability issues.
Another less labor intensive and less expensive option is to chemically clean these engines. It is always recommended to borescope the induction system before and after a cleaning. Never assume that because the engine has been cleaned that the carbon has been removed. This may allow you to think the carbon is not creating the drivability problem when in fact the carbon has not been change by the cleaning. Over the years chemical cleaning his has proven to not be a very effective method. Anyone that has checked the carbon deposits with a borescope before and after cleaning knows how ineffective the industry chemicals really are.
However, there have been recent developments in the chemicals and delivery systems that now provide excellent results on GDI engines. In order to remove these unwanted carbon deposits, we need to understand that this is a two-part problem. The first problem is the effectiveness of the chemical itself. The second problem is getting the chemical to the carbon deposits. Both the chemical and application method will need to be designed to work together in order to optimize results.
Revisiting chemical cleaning options
In order to understand how these carbon deposit can be chemically removed we must first understand the carbon itself. The carbon structures that are produced in the GDI are very different from engine to engine. The carbon accumulation within an engine will vary depending on many different variables such as; the type of hydrocarbons the fuel is made of, the detergents added to the fuel base, the type of hydrocarbons the motor oil is made of, the anti-friction additives added into the oil, the operating temperature of the engine, the pressure the carbon is produced under, the load on the engine, the engine drive time, the engine drive cycle, and the engine design. Each of these variables will affect the type of carbon that will be produced and amount of carbon accumulation within the engine.
Perhaps the largest contributor to these GDI carbon accumulations is the engine lubricant. In the GDI engine there are different anti-friction additives put into the oil base. The purpose of these additives is to help the oil during the extreme loads put on the cam lobe that drives the high-pressure fuel pump. The engine oil passes into the induction system through the Positive Crankcase Ventilation (PCV) system, along with the anti-friction additives that have been put in the oil base. These oil and anti-friction additives will change the carbon’s structure, thus different oils and additive packages will make different carbon types.
Each type of carbon has a different chemical bonding structure that may interact with the cleaning chemical very differently. This means that the chemical will need to be formulated to work on a wide variety of carbon types. The better the chemical is formulated to work on many different carbon types, the better it can remove them from the largest variety of makes and model vehicles. In order to remove multiple carbon types from diverse engines, a new technology has been developed using an entirely new base of chemicals. These new chemicals can rapidly dissolve multiple carbon types within the engine.
The second problem is delivering the chemical to the carbon deposit site. If you have engineered the best chemical and cannot deliver it to the carbon deposit then you still cannot remove the unwanted carbon accumulations.
Figure 5
For the last 30 years the industry standard has been the use of an oil burner nozzle placed in front of the throttle plate as illustrated in Figure 5. The oil burner nozzle provides a fine spray that puts the chemical in an aerosol format needed to keep the chemical suspended in the airflow that is moving into the running engine. The problem is that the nozzle’s fine spray is hitting the throttle body and throttle plate. This allows the fine spray to impinge on the throttle components thus no longer being in an aerosol format.
One may think that once the chemical has impinged on the throttle plate and housing and is pulled in to the gap between the throttle bore and throttle plate (shear plain) that the airflow would break these droplets up. However, when the chemical enters the shear plain there is turbulent airflow that carries the chemical droplets and redeposits them on the back side of the throttle plate. The chemical droplets then congeal together and become larger. The moving airflow then picks these chemical droplets off of the throttle plate. At this point the droplets are too large to be suspended and carried by the moving air column, so they fall out and pool in the intake manifold. The airflow moving through the engine will drive these pools of chemical along the manifold floor. If the chemical can in fact remove the type of carbon that is in the engine, it will cut a channel through the carbon. This carbon channel will now create turbulent airflow that will cause incomplete combustion events decreasing fuel mileage between 1-3 miles per gallon. This channel can be seen by using a borescope after the cleaning process has been completed. As you can see the chemical must be delivered in a manner that completely covers the entire intake valve and intake port area in order to properly remove the carbon deposits.
Figure 6
Yet another industry standard that has been used for many years to apply chemicals to the engine, is the use of a pressure differential (vacuum) created by the engine. In this method the engine is used to suck the chemical out of a reservoir. These systems use a type of aerator that bleeds air into the chemical flow thus aerating it. Over the years these systems have also been proven to be ineffective. This is because the droplet size produced by this type of device is too large to be suspended and carried by the airflow into the running engine, as illustrated in Figure 6. These chemical droplets will fall out of the airflow and pool in the intake floor thus only cleaning the port floor area, as can be observed by the use of a borescope before and after cleaning.
Making it work
One can clearly see that the chemical will need to be put behind the throttle plate in the form of an aerosol consisting of small droplets of chemical that can be suspended and carried by the moving airflow that will completely cover the intake valve and port area. If the chemical can reach the carbon deposit, and is effective at dissolving the carbon type, the carbon deposit can be removed.
To create this chemical aerosol a high-pressure device such as an injector is needed. This must be located behind the throttle plate in order to prevent the chemical from impinging on the throttle components, as illustrated in Figure 7. This will create a chemical aerosol format that the airflow can actually carry. Now that we have addressed the second problem, the application method, it will be important to address what effect the chemical mixture has on your health.
Figure 7
Many of the industry chemicals used are not good for one’s health. Take one such chemical that is in many of the industry chemical mixtures, N-methyl-2-pyrrolidne (NMP). This is a known carcinogen that can cause testicular cancer in males. This chemical will also damage the paint and plastic components on the vehicle. So care must be taken when using these chemicals. It is important to always read the Safety Data Sheet (SDS) and to understand what health hazards these chemicals might present. Many of the chemical mixtures commonly used in this industry contain chemicals that are rated at a class 3 or class 4 health hazard in the HMIS system. Always follow the proper safety procedures when handling these type chemicals. At one time it was thought these type chemicals were needed to remove the carbon deposits from the engine. New technology has found less harmful chemical mixtures that can effectively remove carbon deposits without these extreme health hazards.
The gain that chemical cleaning provides on these GDI engines is exponential. The chemical cleaning can remove these unwanted carbon deposits from these GDI engine at a cost-effective point. Additionally, if you think the carbon deposits are creating a drivability problem you can clean the engine and eliminate the carbon as a possibility without the costly manual cleaning procedure. The GDI engine can now be cleaned as a maintenance service every 30,000 mile thus keeping these unwanted carbon deposits to a minimum so the engine performs at its designed horsepower and torque output. This will add revenue for your shop as well as provide a needed service for your customer. The power and response that a cleaned GDI engine will produce will astound you and your customer.
Social media is an amazing thing in my opinion. From a diagnostician’s perspective, having the ability to reach out and communicate (in an instant) with like-minded individuals across the globe, allows for some tremendous opportunities. Each one of us sees through a different perspective, has different experiences with different vehicles and can offer data that we might not encounter otherwise. With a group of like-minded individuals that both share a passion for the automotive industry and a desire to learn/share/educate equally, it’s a winning combination. Its these very traits that helped to make an important and otherwise expensive diagnostic decision, easy as pie.
Same problems, different terminology
Earlier this month, I crossed paths with a fellow tech by the name of Ryan Colley. Ryan works in a shop called Elite Automotive Diagnostics, located in a small village called Bishops Hull, in Taunton, United Kingdom! Ryan reached out to me because both of us network commonly with other techs through a few Facebook automotive groups. Each one of us in the groups has a particular arena that they are comfortable in. I happen to be comfortable analyzing pressure waveforms acquired from different points on the vehicle. This is the reason Ryan reached out to me. Ryan is faced with a 2006 Audi S4, housing a 4.2L DOHC-V8 engine under its hood (or should I say “bonnet?") as seen in Figure 1. The engine performs very poorly and was brought to his workshop for analysis. Ryan quickly recognized the symptoms the vehicle — with 77,564 miles and an automatic transmission — was exhibiting, as the cranking cadence of the engine indicated something mechanical is “going to pot.” The vehicle’s PCM was scanned for DTCs. Looking at the DTCs, we can see that misfires are being flagged for cylinders 5,6,7 and 8. The DTC pertaining to the bank 2 camshaft position is the “cream on the plum pudding.” All of the supportive evidence thus far indicates a shift in camshaft timing on bank 2 of the engine.
Figure 1
Ryan had the sense to employ some testing techniques that were both easy to perform and delivered an abundance of diagnostic information. The resulting data from the DTC scan also guided him to the next logical test that was more involved, but would lead him to a more pinpointed answer, regarding the root-cause of the fault concerning this vehicle. Ryan doesn’t shoot from the hip with his diagnostic approach. He lets the easy tests justify the need for more involved tests (no “guess-work” — just logical, solid testing techniques).
Logic told Ryan that the results of a relative compression test would further back-up his theory. Ryan performed the test using an amp probe and a lab scope. The current flowing through the starter supply circuitry is measured and plotted over time on the lab scope. After the engine is disabled from starting and is cranked over (for a few cycles), the resulting current draw is plotted as a trace and presents as a series of “peaks.” If this Audi exhibited no mechanical fault, and because all eight cylinders are engineered the same, they should place the same load on the starter (as they approach top dead-center of their respective compression strokes). Ryan’s theory (due to the supporting evidence) is a mistimed camshaft on bank 2. Ryan anticipates a relative compression capture displaying a variation in “peak amplitude” comparing cylinders from one bank to the other bank. Figure 2 is the result of the test and confirms Ryan’s hypothesis. Ryan sees the variation in peaks but it doesn’t exactly represent the waveform he anticipated seeing. It appears to have a few back to back peaks of low amplitude and the fear is “engine damage,” sustained from the loss of camshaft timing. Ryan proceeds with yet the next logical test procedure, drawing him closer to a diagnosis and recommended course of action.
Figure 2
What would your next test be?
It’s quite clear that the engine is out of time. The questions then become:
Is the valve train damaged?
Is there damage to the pistons/lower end?
The questions are logical but they hold a bit more significance then they first appear to. The configuration of this engine places the timing cover on the rear of the powerplant. To even visually inspect the timing components requires removal of the front-end of the vehicle, the engine/transmission assembly and they then must be separated from one another, as the timing components are sandwiched between the two units. To replace the timing components requires the better part of a 30-hour job! Completing the repair is no easy task, to say the least. Consider the situation if the timing components were replaced, but the engine sustained damage, unknowingly!
Ryan consulted with his coworkers and most all agreed the best course of action was to recommend replacement of the engine. He knew that acquiring the resulting pressure waveforms (from the intake manifold and within the cylinders) may offer a bit of insight as to the true condition of engine overall. It may also tell him if the resulting drivability fault was simply due to incorrect cam timing or not. This of course, would allow him to offer the proper solution to the customer, and do so with confidence.
Figure 3
Figure 3 is a capture representing pressure changes inside the intake manifold. To acquire this data, Ryan affixed his pressure transducer to the intake manifold and coupled it to his PC-based lab scope. The engine is once again disabled from starting and the engine is cranked over for multiple engine cycles. What’s great about these tools and process is Ryan can acquire this data as an active file and share the resulting captures via email or through chat groups like Facebook offers, directly. First, Ryan’s concern was of the seemingly similar random-looking pressure changes in the intake manifold. He was interested in tying the results of the capture to a loss of cam timing on one bank. This is where I come in to play. Let’s analyze the waveform.
First, using a point of reference (from a known ignition event) I was able to determine when an entire engine cycle began and ended. This allows me to capture the data reflecting each of the engine’s pistons contributing to the intake manifold. Researching the firing order is necessary to determine how the activity in the intake manifold correlates with each of the cylinders. A piston chart was added to the capture to aid in analysis (and in explanation to Ryan) as to what I see occurring in the data. We have to first understand that as each cylinder enters the induction-stroke portion of the engine cycle, the intake valve for that cylinder is open. This piston will descend and inhale the fresh air from the intake manifold. Since we are viewing data from the perspective of the intake manifold, each one of these induction events results in a momentary increase in intake manifold vacuum. This causes the trace from the pressure transducer to decrease in amplitude (or “head south”). We can call these events “pulls.” We are interested in seeing which cylinder created which pull.
Cursors are spanned the entire engine cycle which offer the ability to partition the capture in to eight equally-spaced areas. These areas represent the eight cylinders contributing to the intake manifold vacuum trace. Using the cursors, I’m interested in seeing when these pulls occur, relative to the vertical cursors. A late pull will occur further from the cursor than a pull which occurred on-time. Indicated by the gray circles, these represent the pulls from bank 1. Take notice to the cursor, just left of the circle. Indicated by the yellow circles, are the pulls from bank 2. Take notice to the cursor, just to the left of the circle. If you compare the proximity of the circles to the cursors, it’s clear to see that bank 2 pulls are occurring later than bank 1 pulls. This also explains the random-looking pattern of the cranking intake vacuum trace.
Figure 4
Using a piston chart to aid in analysis and explanation, and now referencing the yellow dots superimposed upon it, it too makes it clear to see that all of the bank 2 intake pulls are late, relative to the bank 1 intake pulls. Logic supports a bank to bank timing issue, and we would anticipate every other pull to be late. That would be true in many cases, but not in this Audi’s case. Take a moment to view the engine configuration in Figure 4. The firing order on this engine’s configuration supports a firing event that alternates between banks…. except when cylinders 6 and 8 fire. They are two cylinders that fire consecutively ON THE SAME BANK! This is what you see occurring in the intake trace for pulls 1 and 2 (as indicated by the red numbers, at the top of the capture. These numbers are calling out the cylinder responsible for the pull below it. If you then reference the piston chart, you will see that I have encapsulated an area with a yellow box. This area contains two black stars that indicate when cylinders 6 and 8 approach TDC/compression consecutively. Because the bank 2 intake cam is late, the intake valves for bank 2 cylinders will open late but close late as well, leaving more volume to be shed back to the intake manifold, as the pistons approach TDC/compression. This is why the intake trace rides “hi” for so long at this point (two consecutive cylinders pumping extra volume back to the intake manifold). This is why it has that random-look to it. The appearance of the trace is due to engine configuration.
Figured that out! On to the next step
This data will tell us why the cranking intake vacuum waveform appears as it does, but more significantly, drives us further to the next logical test. A running in-cylinder pressure waveform was acquired form an easy-to-access cylinder on bank 2 (the suspect bank). The pressure transducer is used in place of a mechanical gauge and reveals a tremendous amount of data, and not just peak compression. Because the data is captured on the lab scope, with cursors we can effectively associate time with the 720-degree engine cycle. In other words, we can confirm camshaft timing (to within a few degrees of accuracy) as well as monitor the breathing characteristics of the cylinder, dynamically.
Figure 5
As can be seen in Figure 5, the running in-cylinder compression waveform (for one from the suspect-bank) is captured and annotated. The cursors denote the characteristics supporting the late intake cam timing, as suspected. The red annotation indicates low running compression for this engine. The orange annotation demonstrates the point where the intake valve opened. The cause of the deep in-cylinder vacuum (at almost 24” hg) is due to the piston descending down the cylinder with the valves closed. Only when the intake valve opening finally occurs is the vacuum relieved. Finally, the intake valve is seen to be closing at about 127 degrees ABDC of the induction stroke. These are all key indication of a late intake camshaft. The key is that the captures display what the symptoms offer as suspect. The real prize is the fact that we can see a suspect bank’s cylinder draw a vacuum and create compression with no leakage…all without disassembly and from the other side of the great Atlantic Ocean! Ryan now has the evidence to prove he may begin this saga of a repair. More importantly, he has the confidence to do so. This now perpetuated by his newfound knowledge, his understanding of the pressure waveform analysis!
Figure 6
The better part of a week goes by and I receive another Facebook video capture. Ryan completes the disassembly and confirmed bank 2 intake cam was indeed “late”. The cause of the retarded camshaft was due to a damaged VVT actuator, where the locating pin interfaces to lock the actuator in place (Figure 6). Ryan replaced the timing components and reassembled the vehicle. The engine starts, runs smoothly but the best part was Ryan’s excitement. He was dead chuffed! I only wish I could’ve been there to see the look on his fellow employees' faces!
Shortly thereafter, I received the resulting post-fix captures. The in-cylinder trace reflected strong running compression, an intake valve that now opened on-time at about 16 degrees ATDC. This allowed the piston to inhale freely and prevented the deep in-cylinder vacuum we witnessed earlier. The compression began to increase way earlier as well. The intake valve now seats at about 60 degrees ABDC. Much better than previously (Figure 7). The cranking intake vacuum waveform now exhibits pulls whose proximities are all very close to one another, regarding where they fall, relative to the vertical cursors (Figure 8). This is indicated by displaying both the YELLOW dots (representing bank 2 pulls) and the GRAY dots (representing bank 1 pulls).
Figure 7
Figure 8
We can all now see how difficult gambles can be avoided by moving forward with technology. Learning, by sharing information with peers all over the world and employing newer testing techniques that allow you to make tough calls with the utmost confidence.
How many times has this scenario played out at your shop? A regular customer comes in late in the day, perhaps close to closing time, complaining about a driveability problem that you have been chasing intermittently. Moreover, they exclaim “it’s doing it right now. Do you have a minute to go for a ride with me?" Your extinct as a consummate service professional kicks in — you grab a shop towel, wipe your hands and grab a floormat — and away you go. If you are lucky, you get to duplicate the customer’s complaint, at which point you use your power of observation and keenly honed senses to make a judgement on what ails the vehicle. Perhaps you suspect a misfire and use the old “I feel it in the seat of my pants” so it has to be ignition adage…and so on.
Wasted effort
We have all operated at one point or another this way for many years. However, there is one distinct flaw in the methodology that was overlooked. Anyone who has attended any of my training classes has heard me rail on this. There are few things in drivability diagnostics that I feel are more useless than driving a vehicle on a diagnostic test drive without having a scan tool hooked up to the DLC. The second thing that drives me crazy is when a tech test drives a vehicle for a diagnostic issue and fails to record and save a snapshot. Our scan tools have gotten so much more powerful than they were in years passed.
The buffer size, the memory inside the scan tool, can store immense amounts of valuable diagnostic data that can aid in improving the diagnostic process. This article will examine some diagnostic test drive techniques that will hopefully help techs gain valuable diagnostic direction and help eliminate certain possible causes by using scan data analysis to “take them off the table.”
My friend Scott Shotton once stated something in a class that resonated with me, “There is a fine line between efficiency and laziness…I choose to be efficient.” I can think of no greater way to maximize efficiency other than using a scan tool to garner as much information with the least amount of effort! This method involves diagnosing a vehicle by simply analyzing scan data and creating a plan of attack (POA) and “designing the experiment” to test the system(s) believed to be at fault. Furthermore, if I have the snapshot saved, I have valuable sales tools and documentation to share with the boss or the vehicle’s owner. In addition, we now have a pre-repair movie that we can use for comparison post-repair.
What's the point?
So how do we leverage the technology of the scan tool buffer and combine it with a diagnostic test drive? First, I want to be able to use scan data to learn a couple of fundamental things; how well is the engine being fueled and how well is the engine able to breathe.
Good fuel enrichment
We are going to use the oxygen sensors and fuel trims to tell how well the engine is “fueled” and learn if the Engine Control Module (ECM) is in control over the fuel system. We can accomplish this by performing a Wide Open Throttle (WOT) acceleration or by an aggressive brake torque in reverse. On most vehicles, when we go WOT the ECM drops out of closed loop operation to a fixed open loop fuel map that allows for maximum fuel enrichment that should reveal itself in the upstream oxygen sensor(s) going full rich, or well north of 800mv on a traditional zirconia style (Lambda) sensor. If I have a hesitation under load complaint and I aggressively accelerate and see the upstream sensors going to 850-900mv, what does that tell me about the fuel delivery system and the ECM’s ability to fuel the engine? I can, with a fair degree of certainty, eliminate the fuel pump, fuel filter (if equipped) or restricted/dirty injectors as a probable cause of this.
What other Parameter Identifiers (PIDs) should be I be recording? How about the ones that will allow me to make a Volumetric Efficiency (VE) calculation on a MAF engine if necessary? Some of you may not be familiar with term Volumetric Efficiency. VE is an engineering term that formulates how well a pump can move a liquid or gas compared to its physical limitations. VE is used in a variety of industries like oil drilling platforms. First, we need to know the size of the pump, which in our case is the engine. An automotive engine is an air pump of sorts, so we need to consider its displacement. Pump speed is also critical for the equation and so we use engine RPM. These two things are used in the equation or VE calculator to figure out what is referred to as the theoretical maximum.
MAF and RPM for VE calculation
The next variable is the amount of air entering the engine at maximum airflow, so we will need to capture the MAF in Grams Per Second (GPS) and RPM to do this. In addition, some VE calculators require ambient air temperature and elevation as well. Fuel Trims and Loop Status PIDs are not required to calculate VE, can be a handy reference. So, what can I expect from a known good VE run? It depends on a couple of factors, but at my elevation of 510 feet above sea level I expect to see 75 percent to 85 percent on a normally aspirated engine. My red flag number is usually 75 percent or higher is acceptable on these engines. Obviously, forced induction engines (turbos and superchargers) are much greater and usually surpass 100 percent, due to the fact they are “forcing” air in to the engine via an additional mechanical device. These are my rule-of-thumb numbers, which have worked well for me, but be mindful that your results may differ dependent on atmospheric conditions, calculator choice and your experience.
Choosing additional PIDs
I like to make a custom data list, which allows me to choose the PIDs I want to look at as opposed to the groupings the scan tool software developer choses for me. This usually ends up speeding up the refresh rate of the scan tool by not looking at a bunch of unnecessary PIDs not related to the diagnosis at hand. Once I have my list of the PIDs I want, I then go on a diagnostic test drive and make a couple of VE test runs in which I aggressively accelerate through a shift while recording the snapshot on the scan tool. This is going to give me my max RPM and MAF GPS just slightly prior to the shift.
When I say aggressively accelerate, I mean the proverbial “drive it like you stole it” through a shift. I had a trainer friend that once said if you are unsure of how to make an aggressive wide-open throttle run, grab the 19-year-old kid in the lube bay. They can show you how! (Editor's note: Be sure to follow all local laws and perform your diagnostic test drive in a safe area.)
So on to the diagnostic — sometimes referred to as the “flatrater — test drive. After making several heavy accelerations noting if the upstream oxygen sensors go full rich, pay attention to your five senses and how the vehicle behaves.
Misfires in some conditions may be noticed in the seat-of-your-pants feel and can point you in the right direction. Trust your sense of hearing. Do you notice any unusual noises? Your sense of sight tells if the CEL/SES MIL comes on or is flashing etc. All of these things are part of a process that most of us use regularly and just don’t realize that we do it. It is almost second nature to the seasoned drivability tech. What is imperative is that we have the scan tool setup properly beforehand and are recording the whole diagnostic test drive into the buffer.
Sometimes if I am on a really long test drive, I will pause the recording of the snapshot and save the file. This insures that I have my data successfully stored into the memory or internal drive of the scan tool and it will be there for analyzing later.
Reviewing the data
There are three things I like to analyze back at the shop when reviewing my snapshots or scanner movies. I make my observations under two distinctly different operation conditions; normal cruise state driving and Wide Open Throttle or WOT. In general, this is what I expect to see:
The upstream oxygen sensors should cycle rich/lean in "Closed Loop" and should peg full rich on most vehicles under the heavy load created during my WOT acceleration. I also want to examine my MAP PID as well at idle or steady rate cruise. I want to see it steady and when I accelerated aggressively and deplete the vacuum in the intake manifold, I want to see it go very close to Baro or atmospheric pressure.
Consequently, what would I expect to see if I were monitoring my fuel trims under the above conditions? I should see my fuel trims in closed loop slightly switch or moving about under steady state cruise revealing the subtle PCM correction to achieve and maintain something close to stoichiometry. How about when I go WOT? How should fuel trims behave then? The answer is “it depends.” But what I should expect is my loop status to change from closed loop to open loop. This is what allows my PCM to change to fixed fuel mapping that allows for full enrichment on WOT on most vehicles.
VE calculation
I can test drive a vehicle in a consistent manner and capture a snapshot or scanner movie of the data. Then, later in the safety and comfort of the shop, I can calculate VE and also observe the three key things; O2, MAP and fuel trims. Using this fundamental data, I can usually gain some significant diagnostic direction as to where to concentrate my testing efforts. Let analyze some different scenarios. My friend and co-Driveability Guys trainer, Scott Shotton, developed this cheat sheet, which we can use to plug the information into to help us find the most probable cause of the drivability concern we're chasing.
(Image courtesy of Scott Shotton) VE cheat sheet
Understanding the data
Say we have naturally aspirated vehicle that has a hesitation under load/low power complaint. The condition can be duplicated and during the test drive the oxygen sensors go low instead of high during WOT, the VE calculates at 77 percent, the MAP reaches very close to Baro, and the fuel trims were overly positive at cruise, going into Open Loop under heavy acceleration. These things should lead you to the following conclusions. First, the engine can breathe properly — the VE reflects this — so no clogged cat. Second, the intake is not restricted — the MAP reflects this — so a dirty air filter is out of the question. Third, the fuel trims point to a lean condition. And finally, the oxygen sensors not going full rich point to a fuel delivery issue. This is where I want to concentrate my testing efforts. Perhaps a fuel pressure and volume test as well as current ramping the fuel pump would be the next diagnostic steps to take.
Good MAP making Baro - poor fueling
Here's our second scenario. A similar vehicle to the one above with a similar complaint of a hesitation. The test drive reveals the oxygen sensors are falling short of full rich, the VE is calculated at 58 percent, the MAP makes Baro and the fuel trims under cruise are erratic and appear to” follow the throttle blade” with their positive trim trends. While one might find the vehicle may exhibit some of the same drivability symptoms, what is it that differentiates this failure from the previous example? The answer is VE. Does a failed fuel pump affect the engine’s ability to breathe? It does not. So, what could cause a hesitation compliant that mimicked a fuel delivery issue and reflected itself as low VE.
Good MAP making Baro
The answer is an air measurement error. What measures the air entering our engine and its PID is mission critical to the VE Calculation? The MAF sensor. It has been my experience that most MAF sensor failures tend to overestimate airflow at idle and underestimate airflow under load. While a failed MAF doesn’t affect the engine's ability to breathe, its does affect the VE calculation. It’s the old Garbage In = Garbage Out (GIGO) formula.
Bad MAF fuel trims
Now let’s switch things up a bit and look into some issues that may very well exhibit some of the same drivability symptoms and are revealed in the flatrater test drive by low VE. They are issues that deal with engine breathing restrictions. The first is relatively common to low power/hesitation complaints — the exhaust restriction.
After duplicating the complaint and analyzing my snapshot, I calculate my VE and it's low at 65 percent. Looking at my other three key data points, I want to be mindful of the oxygen sensors going full rich and making almost 900mv. Second, my MAP sensor at WOT reads very close to Baro at 97kPa. Finally, my fuel trims appear to be irregular but less so than the bad MAF example mentioned earlier, trending towards the negative rather than the positive. These all point me in the direction of a restricted exhaust/clogged cat, which I now can focus my testing efforts on, using either a backpressure gauge or an in-cylinder transducer.
Restricted intake
Again, VE is calculated and appears to be low, say 58 percent. The review of the other three things show that the O2 went full rich over 850mv revealing no issues with the fueling of the engine. The fuel trims are very close to normal, in this case total trim being +3 percent. But the what was the third thing we wanted to analyze? If you are thinking the MAP sensor’s behavior under WOT, you are absolutely correct! This is the telltale; the MAP usually falls short of making Baro or may make it for a brief moment but then falls away from it. I like the description the MAP will “ratchet away” from Baro. These things and low VE all point to a breathing issue with the engine but on the intake side. You may be asking how can the intake get restricted? The obvious cause is a SEVERELY neglected /clogged solid air filter. I have also seen those supermarket plastic bags get sucked up in the air cleaner box and cover the air filter, thus restricting the intake.
Good Snap-on enrichment capture
I tell techs repeatedly in my classes that the most powerful tool in their diagnostic arsenal doesn’t rest on the tool box — it rests on their shoulders. Analyzing scan data is doing just that, using the most powerful diagnostic tool you have. It illustrates the old adage that states “Work smarter, not harder!” I think that we as techs have been test driving cars ever since we have been working on vehicles, the crux of my argument is if you are going to test drive a vehicle do so with a scan tool hooked up to it. Moreover, if you are test driving a vehicle with a scanner hooked up RECORD A SNAPSHOT! Our scan tools have gotten so much more powerful than years passed, and few techs tend to take advantage of all their features. The scan tool allows me the garner as much as info as I can with the least amount of effort. As with anything in automotive there are exceptions, you can’t say always and works on everything. However, speaking from my experience, the flatrater or diagnostic test and recording a snapshot and calculating VE and be mindful of how my O2s, my MAP (if equipped) and how my fuel trims behave has served me well over the years. I hope you are using these techniques or are open trying them and it helps you streamline your diagnostic process and point you in the direction you need to focus your testing!
How about only one out of eight cylinders? That’s true for 2019 and for the last 20 years there have been plenty of other models in your service bays every week that can run on half of their cylinders thanks to the continually advancing technology of variable displacement engine technology. In this article, we’ll pass along information on how the brand new and older systems work plus give some diagnostic tips on what to do when they you get common variable displacement engine complaints like misfires and oil consumption.
Variable displacement? The whys and the variations
Figure 1
To meet increasing CAFÉ requirements, OEMs have been downsizing engine sizes and adding technologies such as turbocharging and GDI for years. Another technology seen in your service bay to accomplish the same CAFE goal is variable displacement. A full-size pickup or SUV weighing over 2.5 tons travelling 65 miles per hour only needs around 25 HP to maintain speed on a level surface. In 2005, the Generation IV Vortec 5.3L engine in the GMT 360 platform (Chevrolet Trailblazer and GMC Envoy) were the first engines equipped with Displacement on Demand (DoD) if we don’t include those early Cadillac 4-6-8 engines from the early ’80s. The DoD engine control system has the ability, under certain light load driving conditions, to provide maximum fuel economy and reduce emissions by deactivating four of the eight engine cylinders. Cylinders 1 and 7 on left bank and 4 and 6 on right bank are always the cylinders disabled. GM changed the name to “Active Fuel Management” or AFM shortly after that and other OEMs joined in with their own variable displacement technologies such as Chrysler/Dodge/Jeep with their Multiple Displacement System (MDS) used on Hemi engines (almost identical to GM’s system) and Honda/Acura with their Variable Cylinder Management (VCM) system. Each manufacturer has released subsequent variations with minor changes to their systems over the years. Until the 2019 GM full-size pick-up/SUV model engines (5.3 L84 and 6.2 L87) debuted this year with Dynamic Fuel Management (DFM), there had been one aspect of commonality – the same cylinders were always shut down during reduced displacement operation. With DFM or as Delphi Technologies refers to it, “Dynamic Skip Fire”, almost countless combinations of cylinders activated and deactivated will likely become the new normal for variable displacement technology. Delphi teamed up with the software company Tula in Silicon Valley to come up with an innovative technology that constantly changes which combination of cylinders are deactivated. GM’s DFM utilizing eight separate solenoids (Figure 1) to control all 16 valves can rotate cylinder deactivation patterns as well as run fixed patterns. DFM differs from other systems in its charge trapping strategy with a low-pressure combustion charge trapped in deactivated cylinders, requiring deactivating and activating the intake valve before the exhaust valve. For rotating patterns, which cylinders are being deactivated can change with each subsequent engine cycle.
AFM and MDS mechanical operation
GM and Chrysler/Dodge/Jeep use oil pressure control solenoids to move a spring-loaded pin in both the intake and exhaust lifters essentially allowing the lifter to collapse/shorten on command. The solenoids are housed in common assembly GM refers to as a LOMA (Lifter Oil Manifold Assembly) (Figure 2). On both OEMs these locking pins connect the inner mechanism of the lifter to the outer housing. The inner mechanism interfaces with the pushrod; the outer housing contacts the camshaft lobe through a roller. Thus, the lifter doesn’t lift as far when the cam lobe moves it up therefore the push rod doesn’t push as high and the rocker arm doesn’t open the valves (Figure 3). Although one solenoid controls lifter pin release pressures for both intake and exhaust valves, solenoid activation is timed so the exhaust valve is disabled first. This traps a burnt exhaust charge in the cylinder which contributes to a reduction in oil consumption, noise and vibration levels and exhaust emissions. If all enabling conditions are maintained for variable displacement operation, the PCM calibrations will limit cylinder deactivation to a cycle time of 10 minutes in V4 mode, and then return to V8 mode for one minute. Transitions from 8-4-8 only takes 250 ms. Fuel is disabled while spark remains active to reduce the potential for plug fouling and cylinder wall wash.
Figure 2
Figure 3
Honda/Acura’s VCM system differs in that it uses solenoid-controlled oil pressure circuits to move spring-loaded pins to cause the overhead cam’s rocker arm assemblies to uncouple from the cam lobe followers (Figures 4 and 5).
Figure 4
Figure 5
Electronics and software strategies
All variable displacement systems work via oil pressure control solenoids. The engine management computer’s job is to activate these solenoids while monitoring for current draw and voltage status. Resistance for each solenoid is around 12 ohms. If, for example, the solenoid’s low-side ground control circuit is NOT commanded to ground the circuit should be at battery voltage. If the solenoid’s low-side ground control is being grounded (to activate the solenoid) the low-side control circuit should be near zero volts. In either state the voltage should be as predicted and if not, a DTC sets for a circuit fault. Nothing new there. The enable criteria for any of these systems to work is lengthy. Basically, there can be no high load or over heat condition nor any DTC setting conditions present for these systems to activate.
Hemi MSD crazy case study
A very interesting case study came up in a John Thornton class I had the pleasure to attend a couple of years ago. It brought to light an unusual side effect of a faulty COP (Coil on Plug) on a Dodge Hemi engine. The faulty COP (even though it was providing spark) was spiking the PCM that controlled the coil’s primary winding. That spike sent the PCM into a software tail spin referred to as a PCM reset. When the PCM resets on a Dodge, the ASD (Auto Shutdown Relay) turns off. PCM resets can occur occasionally or several times per second. In the car John was diagnosing, the reset occurred multiple times per second, causing a buzzing sound at the ASD relay. As John said in his class: “ASD relays shouldn’t buzz!” Along with a drivability fit, the car had an MIL for numerous DTCs. The DTC that seemed to set most often was an MSD solenoid circuit fault. Presumably the ASD clicking on/off rapidly as the PCM reset caused the MSD solenoid’s voltage status to be one of the first things the PCM looked at when it “regained consciousness” after each reset. The tech John was assisting had naturally focused on the MSD relay circuit DTC, which was only a symptom of the root cause – the faulty COP was causing the reset!
Variable displacement engine complaints and diagnostics
Transition too abrupt
Some drivers on today’s variable displacement vehicles can feel the transition. Some calibration changes have been made to reduce the noticeability of the feature either by increasing torque smoothing strategies (Figure 6) or reducing the instances on when the system activates. The Acura I worked on recently had received a software update to address VCM issues (including oil consumption), which significantly reduced highway apply time for the system. On road tests with the Honda factory scan tool, I ran out of patience trying to capture the apply of VCM cylinder shut off during steady interstate driving. As soon as I left the interstate, transitioning to moderate highway/rural driving conditions, the system began its process of running in 3-cylinder mode. I had a hard time feeling any transition though. Performance minded drivers of GM AFM and Dodge MDS equipped vehicles may complain that they can feel their V-8s transition to 4-cylinder mode or dislike throttle response. For many older drivers, there is sometimes historically induced trepidations dating way back to the old complaints from the Cadillac 4-6-8 days. Quite a few Cadillac owners complained about abrupt activation/deactivation transitions and the transmission’s fourth gear input circuit (a major enabling input for the old 4-6-8 system) so that circuit “mysteriously developed an open circuit condition” at the dealer thanks to some customer satisfaction minded Cadillac technicians back in the day. Despite tremendous improvements in these systems today, there are still problems and disadvantages that some owners are unwilling to put up with. The processes involved with deleting this feature on today’s vehicles is covered in numerous owner web blogs.
Figure 6
Contamination/Oil sludging issues
As with engines equipped with variable valve timing and variable valve lift, variable displacement models are every bit as dependent on an ample supply of clean oil. Engine oil sludge and other sources of contamination can cause the pins in the lifters or rocker assemblies to lock in the deactivation state (misfires) or activation state (variable displacement feature not working) resulting in drivability and DTC complaints. Many variable displacement engines include a screen near the oil passages feeding the displacement control solenoids (Figure 7). Today’s variable displacement engines require preventative maintenance services (in this case the common LOF) at intervals based on factory recommendations, real-world experience and the customer’s driving habits. As important as the oil’s viscosity and synthetic/semi synthetic status is the engine builder’s spec for that application.
Figure 7
Oil consumption and fouled spark plugs
Regarding motor oil, a common complaint on variable displacement engines is oil consumption. Theories vary as to why extra oil consumption seems to plague these vehicles compared to their fixed displacement counterparts. There are lots of folks in the aftermarket promoting the deletion of AFM and MDS on GM and Chrysler products. I personally prefer to stick with what the OEM says on the subject of 2007-2011 models equipped with AFM. Take a look at this abbreviated summary of the General Motors TSB 10-06-01-008F:
Condition
This TSB focuses on the common problem of engine oil consumption of vehicles with higher mileage (approximately 48,000 to 64,000 km (30,000 to 40,000 mi) experiencing an MIL and/or rough running engine. Verify that the PCV system is functioning properly. If the customer understands that some oil consumption is normal and still feels the consumption level is excessive, more than 1 quart per 2,000 to 3,000 miles of driving, perform the service indicated in this bulletin.
Cause
This condition may be caused by two conditions:
Oil pulled through the PCV system.
Oil spray that is discharged from the AFM pressure relief valve within the crankcase. Under most driving conditions and drive cycles, the discharged oil does not create any problems. Under certain drive cycles (extended high engine speed operation), in combination with parts at the high end of their tolerance specification, the oil spray quantity may be more than usual, resulting in excessive deposit formation in the piston ring grooves, causing increased oil consumption and cracked or fouled spark plugs (#1 and/or #7)
Correction
Redesigned rocker covers address the PCV oil usage issue. For the excessive oil discharge from the pressure relief valve GM says you may also need to install an oil reflector in the crankcase oil pan near the pressure relief valve and clean/free up the piston rings or even replace the pistons in severe cases along with the spark plugs (of course) if they are oil / carbon fouled. See the TSB in its entirety for complete details.
Engine mechanical misfires and noise
These problems can occur no matter what OEM or design is used in variable displacement systems. Regardless of whether lifters don’t lift (GM, Dodge) or rockers don’t rock (Honda), it’s a small pin operated by the electronic control of oil pressure that does the job. When it doesn’t move to allow for cylinder deactivation there are torque management processes still going on to prevent the driver from feeling cylinders cut in and out. Torque management will continue for cylinders that are NOT deactivated properly until a DTC sets, meaning if the cylinders aren’t shutting off due to stuck mechanical parts, there will be surges noticed under steady cruise conditions. If the engine enters reduced displacement and remains there due to sticky mechanical parts (stuck lifter/rocker pins or solenoid oil passageways), a stumble is noticed followed by a misfire(s). Honda/Acura models will sometimes “hammer” when their V-6 Odyssey minivan models get one or more cylinders stuck in displacement reduction mode. This abnormal noise may even be described as “it sounds like a machine gun under my hood!” Honda addresses normal noise and vibration on their VCM systems via special motor mounts and noise cancellation via the factory audio system. Whether your customer has excessive engine noise or a misfire DTC, you’ll need to add variable displacement system testing to your diagnostic approach when working on these vehicles.
Variable displacement mechanical diagnostic tech tip
Kent Moore has a special tool (EN-46999) for GM’s AFM systems that checks the oil control solenoids’ electrical integrity as well as the actual flow from the solenoids via compressed air and a pressure gauge tied into the system. As with any OEM specialty tool with a high price tag (MSRP of $1,400), unless you find a used one for a low price, you’re probably not going to purchase it. Adapters to the harness and the pressure connections further run up your costs and hassles to do diagnostics the “OEM way” so one alternative to using this and other special tools on variable displacement engines is to perform a running compression test while activating the variable displacement system:
Connect a scan tool that has the bi-directional control capability to activate variable displacement oil control solenoids for the vehicle you’re working on.
Disable the fuel and spark for one of the cylinders that is controlled by the variable displacement system. Choose two variable displacement-controlled cylinders – one that is NOT having a misfire and one that is for this test.
Remove the suspect cylinder’s spark plug and install a compression gauge with the hose’s Schrader valve removed. If you’ve never performed a running compression test you should practice this procedure on a few known good vehicles to get your bearings on what to expect. Generally, the compression you get during a normal speed cranking compression test is at least twice as high as what you encounter on a running compression test. Running compression tests are excellent methods for catching problems such as faulty valve springs which sometimes don’t show up when performing conventional cranking compression tests.
Activate a suspect cylinder’s variable displacement solenoid via your scan tool (or do so manually with fused test leads connected correctly) while observing the compression with the engine running. A properly functioning variable displacement system will cause the running compression readings to increase and decrease as you activate and deactivate that cylinder’s oil control solenoids. If an oil passage way is plugged up, a solenoid is not functioning or there’s a stuck pin in the lifter (GM or Dodge) or rocker (Honda/Acura) you will not see a change in running compression as you activate that cylinder’s solenoid. A deactivated cylinder will typically run around 20 PSI on a running compression test while the same cylinder will jump up to around 50 PSI upon reactivation if that oil control solenoid is working, the oil passageways are clear, and the lifter is working as designed.
Note: If you know how to perform an in-cylinder pressure transducer test with your lab scope, leave the compression gauge in your tool box and use the transducer to look for changes in cylinder pressure as the oil control solenoids are actuated. Your initial pattern upon cylinder deactivation will show two larger pressure pulses for both intake and exhaust (almost identical in amplitude) followed by lower and lower pulses until the cylinder is reactivated (Figures 8 and 9).
Figure 8
Figure 9
There’s an abundance of known fixes for popular variable displacement engines as they near their 15th year in the field. The brand-new GM DFM/dynamic skip fire systems that fire and skip cylinders with deliberate and intelligent patterns will undoubtably bring a whole new set of problems and fixes yet to be discovered and developed. Rest assure of one thing that’s not variable – Motor Age’s mission to keep you informed!
What does it mean when a person says that they “believe” something? In my view, the term is often misused. I see the word “belief” as having deeper meaning than what society often allots to it. It is probably more accurate for a person to say “I think” or “I guess” rather than “I believe,” because the latter implies that you are certain of its truth. Our beliefs form the foundation of our view of the world, and act as our compass when we make decisions. Beliefs may even be important enough to an individual that they are willing to fight for them.
Some of our beliefs have been stated so many times that they can now be classified as platitudes. A platitude is a moral statement that has been overused to the extent that it has lost meaning. When we hear the same phrase, over and over, the effect is dulled and it doesn’t grab our attention any longer. Those beliefs (now platitudes) are still represented by a voice in our consciousness, but they are no longer dominant voices and can be easily overruled by other concerns.
Many of us would say that “Safety First” ranks among our personal beliefs. We often don’t give it a second thought when we say it or see it on a poster, because we have heard it innumerable times over the years and nobody seems to ever question it. However, while it seems to be the right thing to say, do we actually believe it and act on it?
Mike Rowe of TV’s Dirty Jobs fame has some interesting thoughts on the subject. Rowe has pronounced the idea of “Safety Third,” which immediately grabs his viewer’s attention. No matter how you interpret his statement, it causes you to stop and wonder who would have the nerve to say such a thing. Taken at face value, Rowe appears to be an unfeeling brute to say that any concern could be more important than safety.
My personal take on Rowe’s Safety Third declaration is that he is trying to get people to think about what they truly believe. And, he is absolutely correct when he says that Safety First has become a platitude that no longer has the desired effect on the listener or the person who utters it. Many of us have been conditioned out of believing that safety should be the dominant concern when we make decisions.
Our problem with the safety message is that it implies an investment, and to some extent, deferred gratification. As humans, we have certain traits that have always been and will never change, and one of those is our bent towards what I call “Faster Easier.” We analyze pretty much every task we perform in terms of how much time and effort it will require to get the job done. Decisions on the methods we will use are often made with the goal of reducing the personal investment required to complete the task. Risk can also be a factor in our decision making, but we tend to downplay the risk if we perceive there is a significant reward waiting for us.
This is where our beliefs come in to play, and unfortunately, many of us cling to beliefs that run counter to the safety message. Worse yet, these are the beliefs that tend to be reinforced by our inclination to Faster Easier. So, while the still, small voice of safety isn’t completely muted, it tends to be drowned out by the voices that advocate for getting the job done as quickly and easily as possible.
So, what are the beliefs that influence our decision making towards putting ourselves and our coworkers at risk? I would suggest that for many of us, these beliefs reside in our subconscious, only making themselves known when we are under pressure to get a task done. Let’s take a look at some common examples, and consider carefully whether we grant them safe harbor in our personal belief system.
Safety and production are two different things - The age-old struggle between production and safety will probably never go away. This is driven by our natural tendency to acquire a case of tunnel vision as we work. In the here and now, it can be enormously difficult to discipline oneself to see the bigger picture, which is that incidents are so expensive that safety has become a solid business decision. When I say incidents are expensive, I’m not just talking about the dollar value. The physical, emotional, and spiritual costs related to a workplace injury cannot be quantified in those terms.
An interesting aspect of this belief is how its voice gets louder as the work day progresses. As the worker draws closer to quitting time, their ability to objectively analyze risk diminishes. That, combined with the overvalued reward of getting home on time often leads workers to make bad safety decisions late in their shifts.
Taking risks makes me a better employee - Some workers believe that their supervisor would prefer them to stick their necks out, if necessary, to get their jobs done. This might be an accurate perception, as it could very well be that their supervisor has made room in their personal belief system for this attitude.
The supervisor has the most control over whether this belief takes a foothold in their workforce. Without even realizing it, they may be rewarding their workers for taking risks by slapping them on the back for getting a job done quickly, while not bothering to ask whether they had done it as safely as they could have. This is known as tacit approval, where the supervisor reinforces unsafe behavior by not asking nor saying anything when they suspect their workers are assuming inappropriate risk to get their jobs done.
The only way to dampen this voice is to demand accountability from the people who work for you. Think carefully about whether you unintentionally reward your workers for unsafe behavior and consider ways of giving “carrots” to those who do work safely, even if they take more time to get their jobs done.
My shortcut will always work - Faster Easier leads humans to take shortcuts whenever possible. So, for every task we are faced with, we are immediately thinking about ways that we can reduce the time and effort required to complete the job. This may lead us to take shortcuts that could get the job done faster, but might also increase our risk.
Shortcuts are brain candy. When we get a job done more quickly or with less effort, we feel smarter than those who came up with the procedure we were supposed to follow. This also reinforces our resolve to “beat the system” anytime we can, as well as increasing our overall risk tolerance.
When we attempt a shortcut for the first time, we may not know for sure if it will work, so we watch carefully to make sure it doesn’t go sideways on us. However, if we manage to pull it off and nothing bad happens, we immediately start down a slippery slope where we get comfortable and stop thinking about the risks we assume when we take that shortcut. Eventually, the time comes where a variable changes and an incident occurs.
Just because a shortcut has worked in the past, it doesn’t mean it will always work. There are always variables that must align in your favor in order to successfully complete a task. If you get comfortable with a shortcut you’ve devised, your guard is lowered and you eventually stop asking “what could go wrong?” The voice of this belief is much louder now, making it more likely to drown out the still, small voice of safety.
The people you work with could be the best antidote to this belief. Are you open to hearing outside opinions on your work practices? Think carefully about how you respond to your coworkers when they approach you with a safety concern. If you react negatively to a coworker’s efforts to keep you safe, you are sending out a message that you aren’t interested in other people’s opinions regarding safety. This could be your undoing, because your coworkers are going to withdraw from you and won’t be there to serve as the voice of safety when you need them the most.
The rules are written in blood, but not MY blood! - In other words, it won’t ever happen to me. You can pretty much rest assured that anyone who has been injured or killed in the workplace had thought this at one time.
We often associate this belief with the youngest, least experienced workers, but that is a myth. The truth is that this thinking is rampant among workers of all ages, particularly those who haven’t suffered loss due to a workplace injury. The majority of workers who get hurt or killed in workplace incidents are veterans, and in many cases they are within a few years of retirement.
It is sad to say that the most effective method for lowering the volume of this voice is a workplace incident that involves yourself or someone close to you. While this is the most effective method, it is certainly the least desirable. Do your best to learn from the mistakes of others through incident reports and personal stories shared by your coworkers. And, remember that a little humility goes a long way; never allow arrogance to overrule your personal voice of safety.
Someone other than me should be most concerned about my safety - If this is one of your personal beliefs, I would pose this question to you. Who will suffer the most if you get hurt in a workplace incident? Anyone who says that their employer will be impacted more than themselves needs more information. Your employer will be set back on a financial level. However, you could lose everything that is important to you, I daresay everything that defines you, if you don’t work safely.
I would encourage you to do an audit of your personal safety beliefs. This could be a difficult exercise and will require brutal honesty on your part. However, the rewards can be great because purging beliefs that serve to compromise your personal safety will help you, your family, and your coworkers prosper.
It’s no surprise on a hot summer day that a customer greets you at the service desk stressed out over their car. Their car isn’t keeping them cool, it’s uncomfortably hot, they’re perspiring, and they’re probably more than a little temperamental about it. All because today of all days, with all the plans they had made, the car decides to have a non-functioning air conditioner. To make matters worse, the vehicle was recently in the shop (hopefully not yours) for some unrelated work, and now that the air conditioning is out, it most obviously is related to what was done the last time it was in the shop. And, of course, it’s entirely the mechanics fault.
Whatever the case maybe, the real issue isn’t the who done it but what is actually wrong, and how are you going to solve their problem. So where do you start to solve this issue quickly and efficiently?
If this is what you see with the air conditioner on, and the head pressure is rising, start looking for causes and cures relating to the coolant fan and not necessarily the air conditioning system.
As with any diagnostic work, the challenge is to isolate and find the cause and not so much the results that have brought the customer to your door step. We know why they’re here, let’s find out how to get you back on the road. The first thing is to listen to the customer, but keep in mind, the problem can be two fold. One, the customer’s assumptions can be perhaps… misleading, and two, the air conditioner’s lack of cooling the interior may not be the air conditioner’s fault.
For this article, we’re going to go through a few case studies where the cause of the failure wasn’t the previous shop, or the air conditioning system itself. Instead, these studies bring up the point that it could be something that effects the actual air conditioner’s performance. I’m not going to dwell too much on the technical side of the repairs, but on how you can use your investigative skills to read between the lines of the customer’s story and sort out what is really the issue.
Case #1: The dog did It
Besides the customer’s name, phone number, and address, the first thing on any work order should be what the nature of the customer’s complaint is. With that information in hand, you can observe and verify the problem areas of the vehicle using the customer’s explanation as a guide.
“Before we can repair, we must be aware” is my little slogan that I often used when diagnosing a problem.
Now, I know this sounds like the same old thing you’ve read in every diagnostic article, but it’s so true. Do the basics first. Observe, check circuit fuses, grounds and communication. (Not necessarily in that order) Doing the preliminary work is part of every diagnostic even if it’s a drivability concern. Even if the customer only came in because the radio won’t tune to their favorite channel. You have do the basics.
In this particular case, you could have started with checking pressures with a set of gauges, or you could have simply used your thermal gun and checked the system’s temperature at various points to determine whether or not the refrigerant load was within specs. However, sometimes listening and observing (to the car and the customer) is the most important part of the diagnostics.
As his story goes, he uses this particular vehicle as a pilot vehicle for large wide loads that are transported across the country. He travels through various climate zones and long distances with lots of hours behind the wheel. Meaning, a lot of the vehicle’s systems are on for hours and hours. All of which could play a factor in this case, but there’s one more detail that he briefly mentioned just which led to the solution.
The bed of his truck is set up like a traveling hotel room with all the creature comforts of home. He also brings along his favorite companion, a 3-year-old English Shepherd named Jake.
English Shepherds are known to shed their coats profusely, and Jake spends most of his driving time lying down on the passenger floorboard right in front of the recirculation vent. The recirculation system worked more like an automatic fur removal machine than anything else. The blower motor would suck the loose fur off of Jake through the recirculation vent and deposit it on the surface of moist evaporator core where it stuck like glue. After sometime, the fur would collect into a nice flat matt of hair, almost like a layer of felt.
As I listened to his story, my customer had no idea he was telling me exactly where the problem was. His description of how good of a dog Jake was and how he would stay right there on the floor just watching him drive on a hot afternoon also told me this wasn’t a once in a while adventure.
(Photo courtesy of Dan's Automotive Center, Spring, TX) A clogged evaporator core will not only slow the air flow through the core but will cause less transfer of heat. The head pressure rise will be a clue as to what is happening even before you get a look at the core itself.
In this case, the air volume from the vents was the issue. So, why in this case does this problem stick out as the probable cause of the air conditioning failure more than anything else? Listening to the customer’s story intently, knowing that this time of dog has a tendency to let the fur fly, and knowing the operational workings of this particular air conditioning system. It all added up to some simple detective work that arrived at the solution to the problem without a single tool involved.
Obviously, the core had to come out. Once the core had been removed you could clearly see that the evaporator core was a solid wall of dog fur. What is even more remarkable, he didn’t mention or noticed the muffled sound from the blower motor. The gradual clogging of the evap. core had happened so slowly that the eventual drop in the air flow wasn’t even noticed over those long trips.
The solution: Replace the core, clean the ducting, and a new blower motor wouldn’t hurt either. Then, add a filter in front of the recirculation grille to catch the dog hair that could be easily cleaned with Jake had another flurry of loose fur. Problem solved.
Case #2 – Too much pressure
Talk about head pressure! Some customers just have to blow off steam when they come into the repair shop. Whether it’s from some poor information or bad service or they’re just too dang hot under the collar for much more than a good old fashion rant at the service counter. This time around it’s an early 2000 Buick with an air conditioning problem, or at least that’s what the customer assumed it was.
Each time the air conditioning was turned on it would turn off after a few minutes if not sooner. The car was at another shop that had quickly made the call to replace the entire system. This customer wasn’t buying that diagnosis. Again, the key to the start of this diagnosis was to listen to the customer’s story. As in a lot of these stories, you tend to get a bit lethargic, if not sleepy listening them. But you just have to, it’s important.
Think of it this way, don’t listen to the story, listen to what they’re not telling you. I’m actually listening for things like the time of the day, how long they’ve drove the vehicle, or how often the problem occurs. Ask questions like, what were the driving conditions, is it in any way predictable, and ask if they can make the problem happen now. The intermixing of grandma’s chocolate cookie recipe and the kid’s basketball game are not much help in regards to the diagnostic make up but it is part of the story, so you best act like you’re interested in those cookies too.
(Photo courtesy of Dick Kreiger - ConsuLab product is EM-2000HB1234yf A/C trainer) When the radiator fan is off, the high side pressure will rapidly increase until it reaches the cutoff point.
(Photo courtesy of Dick Krieger -ConsuLab product is EM-2000HB1234yf A/C trainer) Normal high side pressure should hover around 175 psi. with everything working correctly.
After pulling the car into the service bay the first thing to do was to simulate the problem and observe the results. I always say that diagnostic work involves looking and examining, not repairing or adjusting. Whether that includes a scanner read or just quick lean over the fender it all falls under the umbrella of the diagnostic fee. However, if you move, disturb, change, adjust, or tighten a bolt you’re NOT diagnosing. If to further your diagnostic work you have to install a drive belt, evacuate and recharge the system, that’s not diag. work, that’s part of a repair and you should charge accordingly. You can continue the diagnostics after that particular work has been completed.
This time around, the diagnosis was rather simple. Hook up a set of gauges and observe the pressure changes. As the compressor would click on it would only take a few minutes before the high side pressure started to rise higher and higher to the point it reached the high side limit and drop the voltage to the compressor. In this case, it wasn’t the air conditionings fault at all, it was the cooling fan. No fan pulling air through the core raised the internal pressure of the air conditioning system to the danger point.
The solution: replace the coolant fan. This time around the connections were perfect, just the fan was bad. The best part was the air conditioning head pressure calmed down as quickly as the overheated customer. Just hope grandma has some of those cookies backed.
What’s the future hold?
These days with the “learn strategy” methods of operation, things are quite different. The vehicle’s computer can make little adjustments to various systems to maintain them in the desired range of operation. Things like controlling a desired torque response that compliments what the customer feels while driving as well as shift points and emissions levels. The typical A/C compressor engagement that would drop the rpm level slightly can now be mapped out of the system by adjusting the electronic throttle and the use of the PWM compressors also eliminates the stress on the belt as well as the compressor. (The electrically operated compressors are even eliminating even more of those internal stress loads.)
This can also mean the story from the customer may take on a completely different aspect to the repair. With every component and system that are being interconnected with the next system can make diagnostic work that much more of a challenge. Today unlike in previous years, listening to the customer’s story may be even more important than ever before. The customer’s understanding of the inner workings of today’s cars will be even more limited than in the past. So, cooling off that hot customer at the service counter may take a bit more understanding and listening than ever before. (Might ask grandma for an extra batch of those cookies for your service counter.)
System refrigerant and oil capacities are smaller, R1234yf is more common, and loss due to refrigerant leakage impacts system performance more now than ever. The fundamentals you learned in school or on-the-job still apply when it comes to troubleshooting and servicing these systems but they are increasingly less tolerant of errors, so it's important to pay attention to the details you may have forgotten.
Let's start with R134a
In the early days of R134a, system refrigerant charges of two pounds or more were not uncommon. Over time, though, system capacities have become smaller with the current average hovering just over a pound or so. And there are several models in production (and have been for the last few years) that use a little more than 10 ounces of refrigerant to cool the cabin. When you consider that the industry standard variance is only +/- 10 percent, that means that an overcharge or undercharge will result with a variance of as little as one ounce!
And what does that mean in the real world?
(Photo courtesy of Robinair) The newest machines are certified to recover 95% of the system charge. Preheating the system can help you recover even more on that first try.
Overcharged systems run hotter than they should, experiencing increased compressor head temperatures that can lead to breakdown of the lubricating oil and accelerated wear in the compressor. Undercharged systems are unable to keep the oil circulating through the system and that means oil starvation to the compressor with the same results. Of course, neither condition will be able to cool the cabin as efficiently as a properly charged system.
The R/R/R (Recovery/Recycle/Recharge) machines in use at the time did not have the capabilities needed to insure the full recovery of the existing charge or the accurate refill of the vehicle after the repairs were completed. Roughly 10 - 12 years ago, the SAE established new standards for servicing mobile air conditioning systems under SAE J2788. R/R/R machines made to these standards had to be capable of removing at least 95% of the vehicle's charge and recharge the system to within 1/2 ounce of the desired amount. Unfortunately, there are still shops using their older equipment to service late model systems. And those that did invest in the newer machines are bypassing some of the features in the interest of saving a few minutes on the job.
Today, we're faced with new challenges as more and more vehicles come equipped with R1234yf. The cost of the refrigerant makes recovering as much as possible more important than ever. Even with the recovery capabilities of the latest machines, you can help the process by preheating the A/C system before hitting the "start" button. Simply close the hood and run the engine for five to ten minutes to raise the temperature of the components (and pressure as a result) prior to evacuation. You can also turn the heat on full blast in the cabin to coax more gas out of the evaporator. You'll know you did the best you could if you open the system and don't hear the "hiss" of escaping vapor!
Along with refrigerant capacity, system oil charges have also been on the decline. Here, too, accuracy is critical to a correct service. Too little oil will bear the obvious consequences while too much can actually coat the heat exchangers (condenser and evaporator) internally, reducing their ability to dissipate the heat taken in by the refrigerant.
Heat exchangers (condensers and evaporators) are moving to these flat-tube designs. Note the small passageways and multiple flow paths. You are not going to flush these clean!
And it's not just quantity. It's where you initially add the oil. When we completed a major repair in the old days (compressor and components), we would add half the oil charge directly to the compressor and split the remainder between the drier (accumulator), evap core and condenser. Today, most of the oil is supposed to remain in the compressor - up to 75% in a running system - so be sure you follow the OEM service procedures to the letter.
Keeping compressors healthy
Leaks in the A/C system are inevitable over time. As the refrigerant is lost, the amount of liquid charge available in the evaporator drops and is less able to carry off any oil that has collected there. In the meanwhile, normal wear in the compressor is causing the accumulation of fine, abrasive wear particles to collect in the oil which are then transported throughout the system. Left unchecked, these factors eventually lead to the demise of the original compressor.
But replacing the compressor without addressing the root causes is only asking for a repeat of the failure — often, a repeat that occurs much sooner than it took for the first compressor to die. I'm sure that many of you have seen that little written warranty notice many compressor manufacturers have been including in the parts box. It states the manufacturer's requirement that the system be flushed and the accumulator (and orifice tube) or the receiver/drier be replaced at the same time the compressor is being replaced. Either that, or immediately void the warranty.
Raise your hand if you're following those directions!
I absolutely insist that the accumulator/orifice tube (or the receiver/drier) be replaced whenever I perform an A/C system service; whether it be a new compressor install or a simple leak repair. The main reason for I do so is to insure that what little remaining moisture left in the system after I've had it under a vacuum is contained. I do not, however, flush the system - at least, not all of it - when performing a compressor replacement.
The orifice tube on the left is clogged with a sealant additive while the one on the right is shown for comparison. Perform a check for sealant prior to recovering a vehicle's charge to protect your equipment from contamination.
For a long time now, the industry has been using flat tube, multi-path multi-pass heat exchanger designs. There simply is no way to flush these components and be successful in getting all that abrasive debris out. The only right way to insure that the debris is entirely gone is to replace the condenser and the evaporator as part of the repair. The same is true of any line that has an inline filter or muffler in it. They cannot be flushed and must be replaced.
I've already talked about oil a bit, but I do want to reiterate here that following the OEM procedure for adding oil to the system must be followed. It is also critical that you use the correct oil. If your R/R/R machine has an oil injection mode on it, do yourself a favor and DON'T use it. When your machine is being used to service a number of different vehicles, the oil in it is almost surely cross-contaminated and filled with moisture. You do know that PAG oil, like brake fluid, is hygroscopic, right?
Another commonly missed step is a critical part of the install process. Once the compressor is bolted up, connected and the system charged, be sure to rotate the compressor through several times to prevent the possibility of "slugging" on initial start-up. On some models, this is a problem even in everyday use and the ECM has a special logic in its programming to control initial compressor engagement. Nothing worse than suffering a hydraulic lock on that brand new compressor.
Keeping you and your machine healthy
Another issue that seems to be on the increase is contamination of the refrigerant charge in the customer's vehicle. Counterfeit refrigerants are one cause but not the only one, or the most common in my opinion. There are too many YouTube "experts" that are showing untrained DIYers how to use alternative refrigerants in their systems, including the popular "Dust Off' aerosol designed for use as a computer/electronics cleaner.
R1234yf machines require refrigerant identification prior to recovery and it's a "best practice" on any A/C system you service.
Another source of potential trouble for you and your shop equipment is sealant. Stop by any big box retailer or automotive parts supplier, and you'll see shelves filled with do-it-yourself cans of refrigerant. Look even more closely, and you'll see that nearly every one of them also contains some kind of sealant additive. I'm not going to argue the merits, or lack thereof, of sealants in this article but I will say that I know of no OEM that approves the use of sealants of any kind in any of their systems. And that's good enough for me.
Unfortunately, the DIYers aren't listening to the OEs. And if a little is good, more must be better!
In order to protect your own health and safety (from the possibility of blend or hydrocarbon-based alternative refrigerants that may be in the system) and your service equipment (from ingesting additives that may clog them up worse than eating ten pounds of cheese), I'm going to once again preach to the need to perform a sealant check and a refrigerant identification prior to recovering the vehicle's charge. Basic identifiers can be had for a nominal investment and if you've already taken the plunge into service equipment designed for R1234yf, you know it's not even an option. The high cost of the new gas makes it imperative that you don't contaminate it with any other during recovery and the R/R/R machine requires this step before allowing you to do so.
Speaking of new machines and new refrigerants, it was brought to my attention at the recent Mobile Air Conditioning Society (MACS) conference that many of you are using R134a machines modified to recover R1234yf. I cannot stress how wrong that is, and I don't blame you guys since many of you purchased the refits from "reputable" sources. It is a pure matter of safety that you cease and desist today!
We all know that R1234yf is "mildly flammable" and there are certain safeguards built into machines certified to the proper SAE standards for servicing these newer systems that the old R134a cabinets simply do not have. Another big difference is the R1234yf machine's requirement that a refrigerant identification test be performed prior to evacuation and recovery of the vehicle's charge. Are you doing that prior to pulling in the charge on that retrofit machine?
Considering that you'll be servicing R134a systems for some time yet and the number of vehicles you'll see fitted with R1234yf will just keep growing, bite the bullet and invest in the proper equipment to do the job.
Finding those lost dollars (leaks)
Locating and fixing even the smallest system leaks is also more important; in part, due to the high cost of R1234yf. It's also critical due to the lower system capacities. As I've already noted, even a 10 percent drop in charge will impact cooling capabilities and oil flow through the system.
(Photo courtesy of Tracer Products) Many new cars come with dye from the factory so check before adding any additional dye to the system. If you do add, add 1/4 ounce only to avoid "overdosing" the system.
The most commonly used leak detection method is fluorescent dye, so allow me to offer a few notes on its use. First, it may take a bit longer for dye to circulate through the system than it used to on some models. If you've fixed the big leaks and want to make sure you got them all, ask your customer to return after a few days for a recheck.
It also helps if you match the UV light you're using to the dye and wear the yellow lenses that the dye maker includes with their detection kit. Yes, UV lights operate in a range of frequencies and the dyes can also vary from maker to maker.
To make the dye easy to see, use a UV light recommended by the dye manufacturer. For best fluorescence, the two should be matched
Also, be aware that many manufacturers are adding dye at the factory. It's not going anywhere unless there's a leak so check to see if dye is already in the system before adding any. If you do add some, add only 1/4 ounce to the system. With the lower oil capacities of today, it is easier than ever to overdose the system with dye if you use too much.
A neat tip I also learned at the MACS event (in a class taught by Standard Motor Products' Peter McArdle) may be helpful when you suspect that small leak is in the evaporator core. Park the suspect vehicle in the sun and close up the cabin nice and tight. The idea is to build up the interior heat level to raise the pressure of the refrigerant in the evaporator core and to give the oil that may be coating the interior surfaces of the core to fall to the bottom. The heat increases the pressure of the gas, too, making it easier for the gas to escape.
After the vehicle has sit for a few hours, take a Styrofoam cup and place it under the evap drain tube prior to starting the car and turning the A/C on "max cold". The idea is to capture the first droplets of the water condensing on the outside of the evaporator in the cup. Now use your UV light to look for dye.
The sniffer couldn't detect the leak since the refrigerant was trapped under the protective sheathing but after letting the system run for a while, the dye became obvious.
You can also use your sniffer to check for the captured gases in the evaporator case by sticking it up in the evap drain line prior to start up. Since refrigerant is heavier than air, the fumes should collect in the bottom of the case. On some cars, removing the blower motor resistor allows access to the base of the evaporator as well.
On the high side, hose leaks right at the hose crimps are common. To help you find those stubborn ones, get the system pressures high by running the system for a while and then checking for leaks immediately after shutdown. An option is to use the same tactic I discussed when trying to coax out every last ounce of refrigerant - preheat the system by closing the hood and running the engine until it reaches normal operating temperature. If you live in a warm climate, simply putting the vehicle out in the sun for a while may be enough to push up system pressures and reveal the leak. All of these are techniques you can try using the service equipment you likely already own.
Yes, the fundamental principles that allow us to keep our customers cool in the summer and warm in the winter haven't changed. But the way we have to service these systems to keep them at their peak efficiency has!
I had (have) been writing for Motor Age since May 2000, and so, when I submitted my application for the college instructor’s job in December of that year, I included copies of Motor Age that featured my articles, and to this day, I believe my position as a contributing editor for this magazine was one of the determining factors in landing the job that a whole lot of other guys had applied for. And for those who think they want a college instructor’s job, well, you need to realize going in that it’s as demanding (and sometimes frustrating) as it is rewarding. There were times when I fully believed I had no idea what I was doing there. As of the writing of this article, I am teaching my way through my 19th year and I plan to retire at the end of May from my teaching position.
I’ll still be writing a feature or two for Motor Age every year if Mr. Meier will work with me on that front, but since I’m no longer going to be neck deep in vehicle repairs every week, I’m not sure how many more articles I’ll be able to hammer out, because the articles I’ve been writing for the past 20 years have been real stories from the service bay, and where Motor Age Garage is concerned, that’s the only kind of story that works. My time in the service bay will be limited after May, I’m afraid, and that’s where the photos and stories come from. The point is that, while I’m not saying you’ve heard the last of me, my articles won’t be quite as regular, although, if I can write enough for Motor Age to hang on to my “senior contributing editor” status, that’d be peachy. Time will tell.
During my teaching tenure at the college, I have forged enough of a reputation with those qualified to have work done in this shop to have lots of real-world repair stories, and those are the stories I tell. Most of the customers we serve like the work we do, so they keep coming back for more, and since experience is the best teacher, my people get hammered with a lot of work, and some of it is pretty doggone tough, but that kind of pressure either molds my people into functional techs or drives them away from the profession. I want them to face tough jobs here so they can handle them out there. I consider my program to be “boot camp,” and they either pass or fail based on what they’re able to handle. My desire is for every graduate to be a living legend, but that’s more up to them than it is to me.
“It’s broke” is all they know
We get vehicles hauled in on wreckers, trailers, and yanked by chains, and sometimes when they show up, nobody even called to tell me they were coming. A couple of weeks ago a 2006 Mazda 6 showed up with the complaint that “something happened, and the timing belt came off,” which made no sense whatsoever on this engine, but then, most every service writer faces this kind of thing. Don’t get me wrong; I’m not ridiculing my customers, but for years it has boggled my mind that some of them don’t even know what year model their vehicle is, let alone which engine is in the vehicle, but that’s OK, because we can figure that out as the work order is being written. But then sometimes they’re not sure how to describe what’s going on, they just know the vehicle is “broke” and can’t be driven and they want us to work some kind of magic.
Even after sitting in the yard for a few months, this Fusion still looked pretty good after it was washed.
In the case of the Mazda, we discovered that the idler pulley bolt had broken off flush with its hole, which, as it turned out, was somewhat difficult to access. There’s a thick aluminum bracket between the pulley/spacer assembly and the hole in the block the bolt is threaded into, but the bracket is designed in such a way that the bolt passes through a long notch instead of a round hole on the way to the block. This is something of a blessing, because you can at least see the broken bolt – but on the other hand, if the bolt was passing all the way through a hole in the bracket and into the block, the bracket would probably support the bolt rather than allowing it to flex and break off.
On this Mazda, with the tire and splash shield removed, the pulley area is fairly accessible and we managed to use a left-hand twist drill bit to succeed in snatching that broken off piece of bolt out. Having worked the requisite “some kind of magic” at this point (it’s what we do, ya know), we had found the original pulley and its spacer lying in there, and so I found a suitable bolt the right length in a can of junk bolts (8mm 1.25 thread pitch), and with a new belt and that replacement bolt in place with the original pulley, we got that one going in short order.
Wait, what? Another one?
About 10 days later, a 2008 Ford Fusion 2.3L, FNR5 Transaxle with 212,564 miles showed up on a trailer. Like the Mazda, this one had been sitting in the yard until all the other pulleys were rusty and there were spiderwebs everywhere. And like the Mazda owner, the Fusion owner struggled to explain what the problem was, but it didn’t take long to figure out that this one had broken the same bolt as the Mazda 6 had. This is obviously a high mileage failure due to the flexing of that bolt.
Well, what we knew from experience was that the first thing we had to do was to get what was left of that broken bolt out of its hole, and that was a LOT harder on this ‘08 Fusion than it had been on the Mazda 6, because the broken bolt wasn’t visible at all – that spot on the end of the engine is about two and a half inches from the car body, and removing the fender splash shield didn’t help this time, because we were looking at two thick layers of steel between us and the broken bolt we needed to extract.
It has always been odd to me how we get two jobs alike within a few days of each other with such similar circumstances. Both cars broke the same bolt and both sat in the yard for a few months before anything was done about it. A few years ago we got two identical Ford Explorer Harmonic balancer failures the same week.
I know the guy whose daughter drives this car well enough that I didn’t need to call and ask him whether I could make a nice round hole in the car body to get to that broken bolt. Heck, the hole would be covered by the splash shield anyway, and it’d make the job a lot easier for the next guy. We did some tape measuring and Sharpie marking, and with a 2-1/4-inch hole saw and an arm-twisting DeWalt 1/2-inch corded electric drill, we made ourselves a nice (if slightly off center) access port, but this broken bolt wasn’t quite as friendly as the one on the Mazda had been.
Everybody who works with a drill in situations like this knows that if you spin the bit too fast, both the bolt and the bit tend to get hot, and that makes the bolt harder and the bit softer – which brings the entire job to a screeching halt – literally, since screeching is the sound the bit makes in those situations. A regular air drill isn’t the best tool for this job, because with the air drills we have, it’s difficult to control the speed of the drill. Using a drill bit extension I snagged from the local Harbor Freight (don’t cuss at me, I like Harbor Freight), we managed to use the electric drill and a new bit to put enough of a hole in that bolt to get it out with a screw extractor. Whew!
Okay, now we needed more than just a new pulley, which was all the parts store had to sell us – we also needed the special spacer that goes behind the pulley, but the Ford place had one in stock, along with a new pulley and bolt, all in one neat package for $28.
My problem with this new Motorcraft part is that the 8.8 Metric bolt isn’t (in my opinion) hard enough. If it was, these bolts wouldn’t be breaking off on more than one vehicle. On the other hand, a harder bolt might be a lot tougher to drill out if it did break. I went with the bolt that Ford included with the pulley, and when we installed a new belt, we found we needed to replace the battery, which was badly cracked around the negative cable, and we had to replace the negative cable end as well, but that wasn’t much of a problem. We checked the oil and coolant and fired the Fusion right up – after setting the tire pressures (they were all low), we put it back on the road.
Coolant leak, Nissan style
Back in 1990, I traveled to Panama City Beach with some friends for a Saturday at Shipwreck Island – we were traveling on 2 vehicles, and one of them was a Toyota van, which sprung an odd coolant leak from the joint of a steel heater hose Y on the way back, and they had to stop and refill the radiator about every fifteen miles or so. Panama City is only 100 miles from where I live (they were from Tuscaloosa), and so, that night we parked the van and I told them I would see if I could do something to plug the leak the next morning after church.
With the van jacked up and the tire and splash shield removed, I wire-brushed the place where the water was trickling out of that tee and used a bottle torch and some acid core solder to forge a repair that got them back to Tuscaloosa without a hitch, and in their eyes, I was Superman with a torch. I have since learned that Toyota had issued TSB 007 on 4-15-88 that read this way: To maximize corrosion resistance of the heater pipes on Vans (YR), the material of the heater tubes has been changed from the previous epoxy powder painted steel type to brass. That’s what the dealer put on their Toyota when they got back home, but they reported later – my repair held all the way.
This is one way to get to a tough spot – the caveat would be that, if the hole were sawed in a load-bearing place, body strength might suffer, but that didn’t look like it would be the case here.
Well, just last week about the time we got done with the 2008 Ford Fusion, a 2000 Nissan Frontier that belongs to one of the college welding instructors came to us on Friday afternoon with a coolant leak vaguely similar to the one I had fixed back in 1990 on the Toyota van. One of the heater hoses is connected to the passenger side of the engine block via a steel 3/8 pipe-to 5/8 hose 90-degree fitting, and the Nissan had just that morning began to pee coolant out of that fitting. We took a photo of the leak and zoomed in to decide if it was the hose or the fitting and determined that it was indeed the fitting after all. Furthermore, we had to remove the starter to access this fitting, and we managed to screw it out of there with a 19mm wrench. The fitting was breached from the inside by electrolysis, it appeared, and while we could have welded it, we decided that replacing the fitting seemed more apropos.
Fortunately, this part wasn’t so terribly proprietary that we couldn’t find another one – except that all the other ones we found that day had 1/2-inch pipe thread rather than 3/8. We ran out of time that first day (which was the end of the week) and so the Nissan had to spend the weekend on the lift before we could get a part, but that job ended well.
Another one bites the hook
Another regular customer came wheeling in with an F150 on a roll-back – it had sheared the driver side lower ball joint, and we had to fix that one outside the shop, but it was fairly straightforward. Get a jack and a stand under it, break out the ball joint service set, pop the old ball joint out and replace it with a new MOOG, and the rest is history.
There was also the 2004 Mercedes E320 with collapsed engine mounts that shook the whole car when you dropped it in reverse – we replaced all three mounts (both engine and the tranny mount) which took about four hours, and in the process found a bent inner tie rod, which we also replaced. Interestingly, the dealer he visited had charged him $700 to replace the upper ball joints (which bolt in, list for $80 each and total listed labor time is an hour) then they quoted him $1100 bucks to replace the two engine mounts, which (list price) are $149 each and the labor is 4 hours. Don’t know where that estimate came from. Based on list price and $100 an hour I could come up with about $750 on the mounts, but using the same standard, I could only justify about $300 for parts and labor for the upper ball joints. We don’t charge labor, but I generally have my students check dealer parts prices and labor times for grins.
About that time, a game warden came in on his 98 Chevy K2500 Crew Cab hunting truck with a popping noise in the front end, hubs that wouldn’t engage, and rear brakes that liked to skid when stopping cold.
The four-wheel drive problem on that K2500 turned out to be a missing fuse, but the popping noise was a lot more serious – the frame had cracked right at the place where the steering box mounts, and when we showed him that, he called a friend who, in his words “fixes these all the time,” but he wanted us to handle the brakes. The shoes on the driver side rear were coming apart and it needed both wheel cylinders, but first we had to bang around on the drum hubs to get those big sixty pounders off. The same rust that had attacked the frame had also tried to weld the drums to the hubs, but we made it happen with some skillful hammer work and a shot or two of PB Blaster®. The warden got new rear brake shoes and wheel cylinders, and he was good to go. By the time all these jobs were done, everybody was sufficiently hammered. A load of happy customers and students who are slightly more experienced made it all worthwhile.
Cooling systems! Could there be a more boring topic? That is exactly what I would be thinking if I were reading this article right now, but I would be wrong. Hybrid and electric vehicle cooling systems are anything but boring. They will challenge you, frustrate you and make you yearn for the good old days before all of this started. Unless you have had no internet access, you have probably read that the entire automotive industry is moving towards the electrification of their vehicle lineup. It is time to get the proper training and tools to service these complex cooling systems.
Figure 1 - Refilling the high voltage battery cooling system using a vacuum fill procedure on a 2017 Chevrolet Bolt EV
Two years ago, our automotive technology department received a grant to develop and provide hybrid and electric vehicle training to teachers of automotive programs at high schools and other colleges in our state. The purpose of the training was to help prepare the next generation of service professionals for jobs in the electrified automotive industry of today and tomorrow. We purchased three new electrified vehicles for this training: A Hybrid-Electric vehicle (HEV), a Plug-In Hybrid-Electric Vehicle (PHEV), and a Battery Electric Vehicle (BEV).
As part of the curriculum development process, I began exploring the technology of each of these vehicles. My exploration included completely removing, disassembling all of the high voltage components and documenting these efforts on video for my students. One technology I had not thought much about is their cooling systems. As you will see, some of these cooling systems are very complex with multiple coolant loops, switching valves, one-way valves, chillers, heaters, pumps and dozens of hoses. PHEVs have the most complex systems, followed by HEVs and then BEVs.
All of these cooling systems require special procedures for diagnostics, service, maintenance and repair. For this article, we will concentrate on the liquid cooling systems; however, some hybrid and electric vehicles use air cooling for some of their components.
Hybrid-Electric Vehicle (HEV) Cooling Systems
The first vehicle I explored for our training project was a 2017 Toyota Prius HEV. We picked the Prius for training purposes because it has been the top selling hybrid in the U.S.A. for the last 18 years. Any HEV will have a complex cooling system due to the fact that an Internal Combustion Engine (ICE) is still involved in propelling the vehicle. The Prius is a series-parallel hybrid; this hybrid type has the most complex cooling system when compared to series hybrids and parallel hybrids. The Prius has 5 coolant loops as shown in Figure 1.
Figure 2 - The 2017 Toyota Prius has a two-section radiator, 5 cooling loops, 16 major components, 20 coolant hoses, and 2 electric coolant pumps!
Prius Internal Combustion Engine (ICE) Cooling
The 2016-2019 Prius has four parallel coolant loops that are connected to the upper section of the radiator just for the ICE. This cooling system has 11 major components and 14 coolant hoses!
ICE Cooling Loop 1, for ICE Cooling
ICE Cooling Loop 2, for Expansion and Air Bleeding Loop:
ICE Cooling Loop 3, for Exhaust Gas Recirculation (EGR) Cooling and Throttle Deicing Loop
ICE Cooling Loop 4, for Exhaust Heat Recovery for Fast Warm Up Loop
Prius Power Electronics (PE) and Transaxle Cooling
There is a single coolant loop connected to the lower section of the radiator for the high voltage electronics and transaxle. This cooling system has 5 major parts and 6 coolant hoses.
Power Electronics and Transaxle Cooling Loop
Figure 3 - The 5 coolant loops of the 2016-2019 Toyota Prius HEV
Prius High Voltage (HV) Battery Cooling/Heating
The HV battery on the Prius is air cooled/heated with a single cooling fan pulling in air from the passenger compartment and pushing it out the one-way pressure relief vents in the rear quarter panels.
Plug-In Hybrid-Electric Vehicle (PHEV) Cooling Systems
The second vehicle I explored for our training project was a 2018 Chevrolet Volt PHEV. We picked the Volt for training purposes because it has the longest range (53 miles (85.3 km)) of any PHEV sold in the U.S.A. As you may know, GM recently stopped production of the Volt and has made a commitment to move to a Battery Electric Vehicle (BEV) lineup.
The 2016-2019 Volt has the most complex cooling system I have ever seen in a vehicle! The Volt has 7 coolant loops, 25 major components, 31 coolant hoses, and three electric coolant pumps as shown in Figure 2. The incredible complexity of the Volt cooling systems is a result of having almost all the same basic components found in the Prius HEV plus four additional liquid cooled components:
The On-Board Charging Module (OBCM): Located in the truck area, this module is used when an Alternating Current (AC) charge cord is plugged into the vehicle to charge the HV battery. This module does not develop heat unless the charge cord is plugged in. Although the vehicle is typically powered off while the charge cord is plugged in, it is normal for coolant pumps, fans, heaters, or the Air-Conditioning (A/C) compressor to run to maintain battery temperature.
The Accessory Power Module (APM): Also located in the truck area, this module provides power for the 12V system and charges the 12V battery. It develops more heat when the demand for current in the 12V system increases.
The HV Reserve Energy Storage System (RESS): RESS is GM’s name for the HV battery in their vehicles. It develops heat while both charging and discharging. For optimum performance, the HV battery must be heated in cold weather and cooled in hot weather.
HV Cabin Coolant Heater Control Module: This module is used to heat the passenger compartment with the ICE off.
Figure 4 - The ICE Cooling and Cabin Heating Coolant Loops of the 2018 Chevrolet Volt
Volt Internal Combustion Engine (ICE) Cooling
The 2016-2019 Volt uses three parallel coolant loops that are connected to the ICE radiator. This cooling system has 7 major components and 11 coolant hoses! Additionally, the Volt uses a heated electro-mechanical thermostat that is controlled with a Pulse Width Modulated (PWM) signal from the Engine Control Module (ECM).
ICE Cooling Loop 1, for ICE Cooling
ICE Cooling Loop 2, for EGR Cooling
ICE Cooling Loop 3, for Expansion and Air Bleeding
Volt Power Electronics (PE) and Transaxle Cooling
There is a single coolant loop connected to a PE radiator for the high voltage electronics and transaxle. The PE radiator is actually the upper portion of the A/C condenser. This coolant loop has 6 major parts and 10 coolant hoses.
Power Electronics (PE) Cooling Loop
Volt High Voltage (HV) Battery Cooling/Heating
The HV battery on the Volt uses a single coolant loop with an external coolant chiller (a mini-evaporator connected to the A/C system), and a 1.5 kW internal heater, coolant hoses, cooling manifolds, and cooling plates. These cooling plates have tiny coolant passages. Never use stop leak or used coolant or cooling passage restrictions can occur.
HV Reserve Energy Storage System (RESS) Battery cooling/heating Loop
Figure 5 - The 7 coolant loops of the 2016-2019 Chevrolet Volt
Volt High Voltage Cabin Heating
Cabin heating uses two coolant loops. The Volt uses a HV 7.5kW electric heater in the right front fender to heat the coolant before it is fed to the heater core. In certain low temperature conditions, the ICE can be activated to help add heat to the coolant for additional passenger comfort.
Cabin heating (ICE Off) Loop
Cabin heating (ICE On) Loop. This loop utilizes a one-way coolant flow check valve to prevent cabin heater coolant from entering ICE reservoir with the ICE on.
Battery Electric Vehicle (BEV) Cooling Systems
The third vehicle I explored for our training project was a 2017 Chevrolet Bolt EV (BEV). We picked the Bolt EV for training purposes because at the time, it had the longest range (238 miles (383 km)) of any electric vehicle for less than $40,000. Obviously, there is no ICE to complicate things, but without waste heat created by an ICE, BEVs need a way to heat the coolant for the heater core in the passenger compartment. This means that BEVs have an extra coolant loop that most other vehicles do not have. The Bolt EV has 3 coolant loops as shown in Figure 3.
Figure 6 - The Bolt EV Drive Unit (Traction Motor and Gear Reducer) housing showing the coolant passages with heat sink fins.
Bolt EV Power Electronics (PE) Cooling
There is a single coolant loop connected a dedicated PE radiator for the HV electronics. This cooling system has 7 major parts and 10 coolant hoses.
Power Electronics cooling Loop
Bolt EV High Voltage (HV) Battery Cooling/Heating
The HV battery on the Bolt EV has an external 2.5 kW heater, external coolant chiller (a mini-evaporator connected to the A/C system), and internal cooling manifolds, cooling plates, and coolant hoses.
HV Reserve Energy Storage System (RESS) Battery cooling/heating Loop
Figure 7 - The 3 coolant loops of the 2016-2019 Chevrolet Bolt EV BEV
Bolt EV High Voltage Cabin Heating
The Bolt EV uses a HV 7.5 kW electric heater to heat the coolant before it is fed to the heater core to heat the air in the passenger compartment.
Cabin heating Loop
Cooling System Maintenance Procedures
In North America, HEVs have been around for almost 20 years, PHEVs and BEVs have been around for almost 9 years. I am sure their coolant hoses have hardened, their coolant has degraded, and their heat sinks have started corroding, but they continue to function well. If I operated a service center, I would look into the maintenance guides for these vehicles and selling the required services at the correct intervals.
General Cooling System Information:
ICE and PE Coolants: Each vehicle manufacturer has their own coolant recommendation based upon the materials in which the coolant must flow as well as the operating conditions in which it must exist. Coolants for HEVS, PHEVs, and BEVs are typically the same coolant used in the ICE, but with the following additional precautions and warnings:
Only use newpre-mixed 50/50 Coolant upon refilling the cooling system. Failure to use new coolant, the correct type of coolant, or the correct 50/50 ratio of coolant to distilled or de-ionized water can cause:
Cooling fin corrosion inside the heat generating Power Electronics components leading to poor heatsink performance, overheating, and eventual premature failure.
Restriction of the passages inside the HV Battery cooling/heating plates. This can lead to overheating, setting Diagnostic Trouble Codes (DTC), and HV system shutdown
Loss of HV isolation at a battery coolant heater element. This will set DTCs and shut down the entire HV system.
Figure 8 - HEV, PHEV, and BEV Cooling system
Scheduled Maintenance:
Toyota: The pink colored Super Long-Life Coolant (SLLC) is scheduled to be replaced in the:
ICE, every 10 years or 100,000 miles (160,000 km) and then every 5 years or 50,000 miles (80,000 km) afterwards.
PE, every 15 years or 150,000 miles (241,400 km) and then every 5 years or 50,000 miles (80,000 km) afterwards.
General Motors (GM): The orange colored DEX-COOL coolant is scheduled to be replaced every 5 years or 150,000 miles (241,400 km).
Nissan: The blue colored premixed NISSAN Long Life Coolant used in their BEVs is scheduled to be replaced every 15 years or 125,000 miles (200,000 km).
Tesla: The purple colored Tesla G-48 ethylene-glycol Hybrid Organic Acid Technology (HOAT) coolant in their BEVs is scheduled to be replaced every 8 years or 100,000 miles (160,000 km). Note: Any damage caused by opening the battery coolant reservoir is excluded from the warranty.
Figure 9 - Scan tool control of ICE Coolant Pump during air bleeding procedure
Service Procedures:
Pressure testing: Pressure testing the cooling systems for leaks is permitted; however, keep in mind that some low temperature PE cooling system pressures as low as 5 PSI (35kPa) may be much lower than the 20 PSI (140 kPa) for the high temperature ICE cooling system. Over-pressuring a system could cause coolant leaks and possible component damage. WARNING: If the PE or HV Battery coolant levels are low, the vehicle may not be safe to drive. A leak test and visual inspection must be performed. Some batteries have an inspection plug to check for coolant leaks.
Vacuum Fill or Air Bleed? After draining the coolant, a vacuum fill procedure is required for refilling the PE and RESS cooling systems on the Chevrolet Volt and Bolt EVs. This method works very well at removing the air from these complex systems before pulling the coolant into the system. The Toyota service information only recommends a traditional air bleeding procedure for their PE cooling systems. Many Toyota HEV have air bleed valves to help remove trapped air. I believe the vacuum fill method would work great for the Toyota HEVs.
Scan Tool Usage: After the vacuum fill or traditional air bleeding, an electric water pump must be activated with a scan tool to circulate the coolant and remove air bubbles. If all of the air is not removed from the inverter coolant loop of a Prius, inverter damage can occur and trigger up to 17 non-recoverable trouble codes.
Hose Clamps and Hoses: Some original spring style hose clamps are glued in place on the hose. When attempting to remove the hose clamp, it is critical that the clamp is not rotated or repositioned so that is tears or damages the hose. You must replace the hose if the clamp needs replacing.
Active Shutters: Newer vehicles have active grille shutters to control airflow through the radiator and improve aerodynamics at higher vehicle speeds. A scan tool can test the function of the shutters, and for DTCs, if an overheating issue is encountered.
Summary:
You may have noticed that there was not much information on Tesla coolant system loops; that is because Tesla will only allow access to their service information if you live in the state of Massachusetts. Our school in Utah has a Model S P100D, and I cannot disassemble anything on it without risking a loss of warranty coverage. With more Tesla vehicles on the road today, that will need to change soon, but it will not happen until Tesla trained technicians are available to service these vehicles.
We have covered a lot of material in this article, but there is much more to learn. Hopefully you have learned enough from this article to determine if you need more training on this and other hybrid and electric vehicle topics. These complex cooling systems are critical to the proper operation of these systems. My best advice for you when working on one of these vehicles is to purchase a short-term or a long-term subscription to the factory service information through www.nastf.org and follow the exact procedures recommended by each vehicle manufacturer. Best wishes!
MACS returned to California for our annual Training Event and Trade Show (MACS 2019) on February 20-23 in Anaheim. Many of the industry’s top trainers were there from companies like ACDelco, Bosch, Carquest and Delphi (just to name a few), along with several HD manufacturers like AGCO, CAT and Komatsu. We learned about A/C troubleshooting from Honda Tech Support, what’s going on in A/C repair shops (through Ward Atkinson’s survey report), and saw new technology at the Trade Show.
Possible new EPA regulation coming in 2019
There’s been a lot of activity regarding refrigerant regulations in the last few years, and our recent saga started back in 2015 when the US EPA issued what we call “Rule # 20.” For those of us who work on passenger cars and light trucks, one of its main points said that beginning with model year 2021 vehicles, it would no longer be acceptable for manufacturers to use R-134a. This is mostly due to its GWP (Global Warming Potential), which is said to be 1,430 times more harmful to the environment than CO2 (carbon dioxide).
Following that rule (in fact, the very next day) two refrigerant manufacturers Mexican and Arkema sued the EPA over this requirement. They thought the rule was unfair because the only practical alternative OEM car makers had was to switch over and use the new R-1234yf refrigerant, which is subject to many patents that preventing them (the Plaintiffs) from making it.
Ford continues to be the only OEM who lists the oil type and system charge amount along with refrigerant information on J639 underhood labels for all of their vehicles. This helps technicians know exactly which type of oil belongs in the system and more importantly, how much.
The way they went about the court case was to say that EPA did not have the authority to regulate HFCs because the original clean air act only specified CFCs and other ozone-depleting substances. Since Congress never gave EPA authority over these global warming gases (as is proposed by the recent Paris accord and Kigali amendments to the Montreal Protocol, which our Congress has not yet ratified), EPA is not allowed to regulate them.
Federal Judge Brett Kavanaugh and two others agreed with Mexichem and Arkema, effectively throwing out that part of Rule # 20 back in August 2017. Since then there have been appeals, with the most recent going to the US Supreme Court. However, as Kavanaugh is now an Associate Justice, the highest court declined to hear the appeal, making the lower court’s rule stand.
2019 vehicle counts at PHL Auto Show
43.7% R-134a (139/318)
56.3% R-1234yf (179/318)
In the meantime, EPA issued Rule # 21 in September 2017, which gave us our current refrigerant regulations (the purchase restriction) amongst others such as self-stealing cans. The rule primarily affected Section 608 and was widely supported by industry, so nobody thought it would become an issue.
And it hasn't really, except that EPA is now reconsidering some of those regulations. Although we primarily live in the 609 world here with respect to mobile A/C, we are still affected by what happens with 608 (which includes EPA’s refrigerant management program, under which it regulates the purchase of all refrigerants).
This brings us up to date with what's been going on. But the story’s not over yet.
Back in September 2018, EPA issued a proposed rule (Protection of Stratospheric Ozone: Revisions to the Refrigerant Management Program’s Extension to Substitutes). In it they plan to revisit regulations pertaining to HFCs and other substitute refrigerants. Most of these would have the biggest effect on technicians and companies who work in the commercial / residential / industrial refrigeration markets, such as those technicians who service rooftop air conditioners on office buildings, warehouses, and residential home central air conditioning units.
Party buses and airport shuttles like this have such large interior volumes to cool that one A/C system simply can’t keep up. Note the rear ceiling-mounted evaporator / blower assembly which is driven by an independent compressor and refrigeration circuit that’s separate from the OE dash-mounted unit.
However, there is one line in the proposed rule which could affect those who work in mobile A/C. The line simply says, “EPA is also taking comment on whether, in connection with the proposed changes to the legal interpretation, the 2016 Rule's extension of subpart F refrigerant management requirements to such substitute refrigerants should be rescinded in full.” That’s a mouthful, but basically it means that EPA is considering whether it should rollback the rule requiring technician certification to purchase mobile A/C refrigerants (like R-134a and R-1234yf), along with the requirement for small can manufacturers to install self-sealing valves in those cans.
Should EPA decide to move forward with this rule, anyone would be allowed to purchase mobile A/C refrigerant (with the exception of R-12 which is statutory under the original clean air act).
And while it would also rescind the self-sealing valves, we don’t expect to see them go away. Can makers spent huge sums of money changing over their production lines to manufacture self-sealing cans, and market prices have already adjusted to the change. Plus, the adapters and hose sets are readily available, and getting rid of them now would seem to be unfavorable.
So, at the time of this writing (March 2019), we don't know exactly what's going to happen. All we’ve heard from EPA so far is that they’re planning to announce their next regulation soon (maybe before this year’s A/C season starts), so we’ll just have to wait and see.
Aftermarket modifications of MVAC systems
Sometimes after a vehicle is manufactured by an OE, it’s sent to an outfitter for modification. These can range from luxurious interiors (including rear seat beverage coolers and secondary A/C systems) in limousines, party buses or conversion vans, to converting a vehicle for accessible use. When the technician needs to modify the factory A/C system to do this, they are required to comply with EPA’s SNAP use conditions for the OE refrigerant.
This basically means that if a vehicle was originally manufactured with an A/C system that uses R-1234yf, then the technician needs to keep that system, any additional A/C circuits, and any additional refrigeration loops, as still using yf and not some other refrigerant or blend. This also applies to R-134a vehicles.
Figure 1 - Bus A/C installation varies depending on its configuration. On left is “Type A” made from an incomplete chassis. On right is a “Type D” transit style converted to look like a trolley train car. Note its skirt-mounted condensing unit, just forward of the rear axle
But as you’ve no doubt seen before, not too many of these modified systems are set up exactly the same from one vehicle to another. See Figure 1. That’s just how it is with custom mods. EPA knows this, and from the feedback they’ve received from installers, they provided some guidance for the industry as to what would be acceptable to the regulator.
For example, if a technician is adding rear A/C to an extended van with an existing front / dash mounted system, they are required to use the same refrigerant as the OE. So, if it’s an R-134a system, you must keep it R-134a. Likewise if it’s an R-1234yf system, you must use yf in the conversion, while also following the SNAP use conditions for yf (like using an evaporator that meets SAE Standard J2842).
In another scenario, some modifications require the installation of a second (or even a third), completely separate A/C system. An example would be installing A/C in a school bus or party bus, which are sometimes so big, and have so much interior space that has to be cooled, that even with two evaporators, one compressor just can’t do the job, and so a second compressor with one or two more evaporators is required (Figure 2). Because these buses usually start out as incomplete chassis by the OE, they are not allowed to use yf refrigerant, and R-134a needs to be used in each of the separate systems. However, if it’s a modified complete chassis which originally came with yf, any additional refrigeration loops (including second or third compressors) must be filled with yf and not R-134a.
Figure 2 - This bus actually has three compressors, but only the top two can be seen. The OE is mounted low on the passenger side, while these two add-ons are right up top. Each powers an independent loop, with the three systems using different amounts of R-134a refrigerant.
Primarily the reason is because EPA does not want vehicles running around with two A/C systems that use two different refrigerants, as this presents an all-too-easy opportunity for refrigerant cross-contamination. But they’re also concerned with technicians trying to defeat safeguards (like using service port adapters that convert a system from a low-GWP refrigerant to a higher one).
MACS 2018 field survey
Every few years MACS conducts a survey of both our member shops and non-member shops to find out how A/C service is being performed and what are the most common issues facing technicians today. We ask questions about how many services are performed in a given week, how many of each A/C component are replaced, and even how many problems could not be solved. We had great participation this year, and here’s just a bit of what we learned.
Figure 3 - (Courtesy of Ward Atkinson) Survey respondents serviced 2,073 R-134a systems, which accounted for 26 to 50 repairs being done per week during the 2018 summer season
Shops on average are servicing between 26 and 50 A/C systems during the peak season, and as you would expect, most of the customer complaints are simply, “It ain’t coolin’.” The majority use R-134a, but we’re seeing more yf systems in the aftermarket (more than 200 shops reported working with yf) as some of these vehicles have now been out of warranty for two or more years. See Figure 3.
Compressor clutch failures topped the “Reason for Service” list, followed by leaking service ports, line connections, hose crimps, compressor (case or shaft seal), condenser, evaporator, drier, expansion device and finally, switches (Figure 4). Not surprisingly, the most common yf component to be replaced were condensers, as they’re front and center to ram air and all the road dirt, debris, salt and (in the northeast) winter brine solution that loves to rot them out.
Figure 4 - (Courtesy of Ward Atkinson) We asked shops to tell us their Top 10 Reasons for A/C System Service, broken down by which refrigerant they were working with. Failed compressor clutches topped the list for R-134a, but it was condensers that failed most often with yf. Considering that most aftermarket service on yf systems is for accident repair, this comes as no surprise.
Ward Atkinson, MACS technical advisor, presented this year’s survey data, explaining that since MACS started these field surveys back in 1990, “We’re not seeing the same type of internal mechanical compressor failures anymore like we used to, and that’s because of today’s tighter, lower charge systems. They’re being made to keep the lubricant inside the compressor, and not circulated around in the system.” This means that even as refrigerant slowly leaks out over time, it’s not carrying as much oil with it, and although this leads to eventual performance issues (and the need for service), more compressors are hanging on to cool another day.
We’d bet most shops don’t like to admit to this, but inadequate diagnosis was called out by more than 80 respondents, indicating that a closer look may have been warranted in at least some of those cases. Shops reported most often that a second leak had been found (or maybe it was the original leak that was missed the first time), followed by defective replacement parts and secondary failures.
Another interesting point was learned when we asked which leak detection method do you use, and more importantly, which do you prefer. MACS members use electronic detectors more often, but both groups prefer to use trace dye when possible. This makes sense too, because especially if dye is added by the factory, it should be present at most leak sites by the time it shows up in our bays. Except for those few locations where dye generally cannot be found in an A/C system, the intuitive nature of dye is what makes it so useful. If you see it, there must be a leak, and if you can see where it’s coming from, you know what to repair.
Sealants also continue to be somewhat of a problem with people not wanting to work on exposed systems, although we did find that member shops are more willing to take on the challenge. That likely has to do with a shop’s level of expertise, but we don’t blame those who pass up the chance. One false move and you “own it”, including the potential damage to your shop’s equipment.
Figure 5 - (Courtesy of Ward Atkinson) System flushing is performed by most A/C repair shops, although some won’t take a chance, and prefer to only replace parts. Still most will at least try to flush simple items like lines and hoses, but not more complex items like condensers, evaporators, driers, TXVs, mufflers, and certainly not compressors.
Flushing is a very interesting subject, and whether or not you can flush dirt and debris versus just oil is a big question that often sparks debate. As most people are beginning to identify, you’re probably not going to get most of the big chunks out, but if the little particles can be suspended in liquid, there’s a better chance with them. There’s also the issue if you can even get most of the flush solvent back out of the system, which is a big question particularly for the OEs. Their concern is that any solvent not removed can remain in the system, diluting the oil and reducing its lubrication capability for the compressor. See Figure 5.
A list of models (by OE) that have switched over to R-1234yf
We also wanted to know where shops are buying their parts from, and what is their estimated amount of “defective new” parts. The bulk of responses said they’re getting a pretty good supply of parts (with very few initial defects), of course with the majority buying in the aftermarket. Still OE parts play an important role, particularly with low volume items. And as you’d expect, the most commonly returned “defective new parts” were compressors, electrical components, condensers and hose assemblies.
Finding yf
As part of our continuing effort to document the industry’s changeover to R-1234yf, MACS once again attended the Philadelphia Auto Show to see the new models, open a few (actually all of the) hoods, and see what refrigerant is being used. This year we skipped a few brands we knew had already changed, and specifically scoped out those we had missed in previous years, as well as some we were really curious about. Here’s what we found.
Since dealers sold the last R-134a Jeep (Patriot MK74) in 2018, and now having converted the remaining “old” minivans (Caravans built on the RT platform were supposed to be discontinued but have held on due to high fleet demand), the only remaining FCA model that has yet to be yf converted is the Abarth 124 Spider, which we don’t expect will happen anytime soon. It’s built in Japan by Mazda and finished by Abarth in Italy, so until Mazda converts (any) vehicles (this one’s a cousin to the MX-5 Miata), we expect it to remain R-134a for the time being.
The only newcomer we saw from Ford was the Transit Connect van, which is made in Europe and has been the subject of controversy for some time as many are imported as passenger cars and later converted to avoid a 25% US tariff.
Mitsubishi may only sell three models in the US, but one of them holds the all-time record for the lowest refrigerant charge of any newly manufactured vehicle. Mirage uses only 9.5 ounces of R-134a! See Figure 6.
Figure 6 - Mitsubishi’s Mirage has been the all-time industry leader when it comes to which car uses the LEAST amount of refrigerant, at just 9.5 ounces!
We didn’t check any of the BMW models as they switched their entire lineup for 2018. Same goes for all JLR (Jaguar Land Rover) and Minis. We also tied off other brands that have fully switched this year, including Alfa Romeo, Chrysler, Dodge, GMC, Jeep, Lincoln and VW.
We could only find two holdouts, and not surprisingly they are Mazda and Mercedes. The latter makes sense, as there was quite a controversy over the new refrigerant more than 5 years ago that included MB recalling 432 SL-Class yf vehicles through US dealers back in 2012. And now that EPA’s MY2021 cutoff has officially been revoked, there’s a real possibility that we may not see Mercedes use yf in the States for many years (if ever). As it stands now the only reason they would want (or need) to switch is if they really need the CO2 credits (which most manufacturers of large, heavy vehicles with big engines need to meet EPA targets). But Daimler is in a unique position as they build some of the most expensive, high-end luxury vehicles in country, and as such they command a premium which likely includes a few dollars to “purchase credits” from other OEMs who have extra to sell (such as those who focus on smaller, lighter, more fuel-efficient vehicles with smaller engines, hybrids and/or BEVs). Mazda on the other hand is just exactly that. 2019 Mazdas average 28.2 mpg with their lowest (CX-9) getting 23. Meanwhile MB models average only 20.9 mpg. And with both around 2% market share, you’re not dealing with huge offsets anyway.
Acura converted ILX, MDX and RDX production over to yf, but not all variants. MDX hybrids still use R-134a with ND-OIL11 (POE). And now that Honda uses yf in the HR-V, they have only to change the Fit to complete their lineup.
Hyundai switched a big portion of their systems this year. Santa Fe, Sonata, Tucson, and Veloster now use yf, which gives Hyundai a 2/3 internal majority. And in most likelihood, two of the models we saw with R-134a (Elantra and Santa Fe XL) were probably built right before the factory switch to yf, considering the Elantra GT and Santa Fe base already use it. If that’s the case, they saved hybrid models for last to switch, and as we’ve seen with others, this too makes sense given their added complexity.
You may have heard about Chrysler’s Secure Gateway Module (SGW) but in case you haven’t, it is going to change some things as far as aftermarket diagnostics is concerned. I put together a comprehensive write up on the SGW to help technicians understand how it works, why it is necessary, and how to prepare for service on SGW equipped vehicles. It contains some opinion in addition to information from Chrysler factory training as well as service info pulled from TechAuthority.
What is the SGW?
Let’s start by talking about what the Security Gateway Module is and its purpose. The SGW was implemented in some models in the 2018 model year and all models 2019 going forward. The SGW in short is a module whose function is to keep the communication networks secure. The SGW protects the vehicle networks from being exploited by creating a firewall between two portions of the network with the most vulnerability. These are the telematics/radio unit and the DLC.
So how does the SGW work? It separates the vehicle network into private and public sectors. The public sector includes the telematics unit and the DLC. Everything else on the network is considered private. Access to the private sector of the network is limited without authentication. As of now, authentication is limited to Chrysler licensed devices. I'll get into this in a moment.
(Image courtesy of FCA) The SWG is not a gateway in the sense that you are used to. It's more like a fence, blocking most of the modules from public access.
As for the physical structure of the network, the DLC connects directly to the SGW via a Diagnostic CAN C and a Diagnostic CAN IHS bus. The term diagnostic is used to describe the bus from the SGW to the DLC only. The SGW is also connected to the CAN C and CAN IHS busses on the private side of the network but is often not directly connected to the LIN bus. It is connected directly to the radio via a CAN IHS and sometimes an additional CAN C bus. These are also on the public side of the network. This is important to a diagnostician because although they are not identified as separate networks on the wiring diagram, the signals on the public networks may not mirror the private side of the network. The SGW wiring diagram may make it look like the SGW functions as a central gateway but it is important to note that it is not used to communicate signals among modules on the private side of the network. It serves as a frame gateway and does not provide signal gateway functionality. The SGW does not contain any drivers and does not directly operate or control any vehicle components but rather allows only authenticated messages on to the private networks.
What is authentication?
The SGW authentication process takes place in the Chrysler servers. As of now, there are two tools that will allow authentication through wiTECH 2.0. The Micropod II and a J2534 device. I asked Joey Hendrich at AE Tools to help explain the advantages/disadvantages of these two options.
When using a J2534 device, the wiTECH subscription is registered to the software, essentially locking it to the computer. With the Micropod II, the wiTECH subscription is locked to the tool allowing it to be used on any computer, tablet, or even cellphone as long as a connection to the internet is available.
When working with the Micropod II, the vehicle communicates through the Micropod II directly with the Chrysler servers via WiFi. The browser of said laptop/tablet/cellphone logs into wiTECH to access vehicle communication. Given the path the data is traveling, you would think wiTECH would operate slowly and data would not refresh as quick but it is surprisingly as fast if not faster than most other tools on the market.
The operation through a J2534 device is a little different. A J2534 device works with drivers and downloaded software which is ported to the wiTECH cloud instead of using an internet browser.
With both of these systems an internet connection must be available at all times including during test drives. Most smartphones now have WiFi hotspot capabilities. Using a Micropod II, the WiFi must be registered on the pod as well as the laptop whereas when using J2534 device which communicates via USB, the WiFi must be registered to the computer only. This can make the pod less desirable for use when test driving.
It is important to note that the J2534 wiTECH software only offers coverage from MY 2010 forward. The Micropod II coverage goes back to 2004 on CAN vehicles and covers all models 2009 forward. Chrysler is also using MEGA CAN which is only supported by J2534-3 devices. While a J2534-2 device will work with wiTECH it may have limited functionality on some of the MEGA CAN vehicles. MEGA CAN is used on everything 2018 up but can also be found in the Renegade and Fiat 500 going back to 2015 as well as the Compass, Alfa Romeo Giulia, and Fiat Spyder in 2017.
What does all this mean for us?
Unauthorized devices will be allowed read-only or, what Chrysler calls, passive access to the private network. Passive means the ability to read codes and data but does not include the ability to clear DTCs, perform, actuator tests, special functions, ECU configuration, flashing, or module resets on the private side of the network.
As a mobile tech I have already had a few calls for code clearing and I foresee that demand growing until the aftermarket comes up with a viable solution. There is however, a ray of sunshine for repair shops not yet ready to invest in tooling right away, in that Mode $04 on the generic side of a scan tool will still allow codes to be cleared in the PCM only. When dealing with the engine controller, a sub $100 scan tool from the parts store can have nearly the same capabilities on these vehicles as a five-figure aftermarket tool with the latest updates. It is important to note that many generic code scanners will often show cleared codes as permanent codes whereas the wiTECH will not display permanent codes. This can be important when pre/post scanning.
(Image courtesy of AES Wave) Autel is one company that is offering a bypass cable to circumvent the SWG. It requires accessing and unplugging the SWG module.
FCA opened up access to aftermarket companies in November of 2018. Snap-On, Bosch, Autel and G-scan are all working with Chrysler towards a solution but there will likely be some challenges getting a tool to work with the FCA servers and integrating a solution to the need for constant WiFi. I myself am curious to see if this will look like a normal scan tool operation or use the aftermarket tools as a pass through with the J2534 interface.
I have always said that many of the aftermarket tools are much more user friendly and often offer much better data display and recording features than the OEM tools. I have been overall impressed with the wiTECH software except the data graphing and record functions. These functions might end up being more user friendly on an aftermarket interface.
If you’re on the AESwave email list (if you’re not you should be!) than you have probably seen the 12+8 adapter Autel has released. This cable essentially goes in place of the SGW. It will require removal or access of the unit which is typically located either under the driver’s side of the dash or behind the infotainment unit (the torque spec for the SGW bolts is 44 in-lbs. in case you were wondering). Removing the infotainment unit may not be ideal but since the SGW does not serve any function beyond securing the network it would seem like this should be a viable solution and would provide full network capability. Furthermore, this solution may be useful in diagnosing faults with the SGW as faults in the SGW may mimic faults in other modules. It is also notable that “no communication with SGW” codes do not exist. When using this cable. I might still expect to see communication codes associated between the radio and modules that communicate with it as the circuits will be interrupted.
Why the SGW?
Before you begin to think Chrysler is intentionally attempting to lock out the aftermarket using the SGW, let’s first talk about the security vulnerabilities vehicle owners face across all car lines, how Chrysler has addressed them, and how we may see other manufacturers jump on board with similar systems going forward.
In 2015, hackers were able to remotely take control of a 2014 Cherokee and manipulate many vehicle features including the steering and braking. This certainly wasn’t the first instance of vehicle hacking but it gained the most attention, much of which revolved around a well-documented video of the attack posted on YouTube. The video goes into detail about how the hackers studied potential weaknesses in the system and were able to manipulate them even going so far as to talk about the potential to target specific VINs and control them remotely using the cell networks, without ever needing to make physical contact with the vehicle. This led to a recall being issued on these vehicles and ultimately, played a role in the development and implementation of the SGW.
While the hackers in that particular instance focused on the telematics units, that is not the only weakness in modern vehicles. You will notice that the SGW also isolates the DLC which is what we, in aftermarket repair, are concerned about. Consider how many cheap Chinese dongles I am sure many of you have removed from your customers vehicles in order to connect your scan tool. I would say at least 25% of the vehicles I see daily have a dongle from either an insurance company, a DLC to cellphone code reading device or fleet/mileage tracker. All of these units work wirelessly and many of them transfer data directly through wireless or Wifi networks. It stands to reason that if hackers can hack a factory Chrysler radio/telematics unit, that getting into one of these networks would be less of a challenge. Hopefully I have painted a picture of why this type of technology is necessary and likely to become standard with other vehicle manufacturer.
I am told that other manufacturers like Ford, Nissan, and Subaru are following suit and that they may even be rolling them out in 2019-2020 models. I don’t necessarily think this will make the aftermarket scan tools obsolete however, I do see many changes on the horizon. Maybe the aftermarket tools are able to integrate with the OEM systems which would likely give them OEM capabilities like programming. At the same time, I could see this driving the cost of the aftermarket tools sky high. Either way, changes are coming and it is up to us to be prepared.
Over the last several years I’ve written on many topics related to the technician shortage. We’ve discussed ideas focused on solving that issue, and have illustrated some successes in the field that should encourage you all to believe there is a solution long term. Part of our discussion has been focused on finding the right people that fit our industry; the tactile learner or the youngster who took things apart and put them back together again like we did when we were young. The person who is inquisitive by nature. Some have sought the new generation of young hot rodders who are modifying their Asian and European sports cars producing results that are simply amazing. Others have looked to upgrade the existing vocational education programs in their area in hopes of attracting more young talent to our bays. If you visit the large for-profit institutions, you’ll see race cars everywhere in an attempt to entice youngsters with the allure of motorsports and perhaps the dream of working for a professional team. All of these efforts are worthy and have varying levels of success, but I question if we are looking at the problem through the correct lens.
As I’ve written many times, I’m influenced by the British-American leadership author, Simon Sinek. Two years ago, I heard a profound statement from him that has changed the way I think about our industry and young people in general. He said that the youth of our world that we typically see as lazy, uninspired, lacking direction, un-committed etc., really know what they want in life. It’s as if they are standing at the base of a mountain and can see their dreams and goals at the top of the mountain. However, they can’t see the mountain. When I heard Sinek say this, it was like a sledge hammer had hit me up the side of my head. Society and technology have enabled our youth to get what they want when they want it to the point if they don’t get it instantly or in the time that is acceptable to them, they go another direction.
I immediately thought the answer is simple; we need to describe the way up the mountain! Surely then, as they take the path we describe and enable them to pursue, they’ll find their dream. Or, perhaps they’ll find a scenic overlook on the way up the mountain that excites them even more than their original dream and they’ll pursue that path. No matter, this had to be the answer to the question of how do we attract young talent to our industry. But is it? I still believe it is a key element to what we as an industry must do by defining the career paths for those entering our industry and for those in our industry currently. It is foundational, it is essential, but it is only one piece of the puzzle. My goal in this discussion is to make us consider for a minute that maybe we are describing the way up the wrong mountain.
I think we all agree the type of talent we need to attract are those that have a desire to solve problems and work in a high-tech industry. With the unstoppable onslaught of technology coming into our bays, we need technicians who have an insatiable thirst for understanding, analyzing and solving problems with these technologies. I have news for you all; those kids aren’t entering our industry because we don’t look like that. Sure, we see ourselves as high-tech and try to put our best foot forward with facilities and benefits and working conditions to attract the best, but at the end of the day our industry is selling something the talent doesn’t want. We are selling the wrong mountain!
It is becoming more apparent that we, the automotive service industry, must remodel ourselves in a way that attracts talent to our doors and create a destination that is not what we have today. It must be different with respect to the barrier of entry; it must be different in the way of benefits; it must be different in the way of career pathways, and it must offer the same flexibility in time and life that the other industries that we are competing with offer. We must stand out. We must make our future workers learn about us and go WOW!
We must learn to treat them as technologists, not grease monkeys. And the same goes for the sales and management staff. We are working on highly sophisticated extreme engineering marvels that cost more than the first two houses I owned. Yet we continue to sell on price. Require our technicians to own their own tools and pay them based on flat rate. We put them in a dark hot box and give them a drop light and expect them to be perfect and fast. We expect our techs to work as techs and to never grow in their career. Sure, we train them enough to enable them to repair the next car in the bay, but we don’t ask them what their life goals are and determine if they might want to own their own shop someday. We don’t ask what’s important to them. We offer discounted services to attract new customers and we expect the production team to build the work along with producing the work. And at the end of the day we all look exactly alike and look exactly like our industry did 40 years ago.
So, it seems to me that we as an industry need to totally rethink how we attract young talent. First of all, we need to recognize that we are not going to change all young people and the way they think or the dreams they have. Second, we are not going to change the technology coming into our bays. Third, we are not going to stop these groups of young adults that we struggle to attract from becoming customers (they are already) or business owners (they are already). Fourth, if we don’t start changing today, our industry dies. A stark statement? Yes, but to attract talent we need to transform ourselves into an industry that is attractive.
Finally think about how you position your business as a technology company that is focused on mobile sources. What are your entry requirements? Do you require a degree? Do you assist in getting that degree? Do you provide all tools and equipment? Or better yet, do you have a facility that looks like a technology center rather than a poorly lit dungeon. Do you have a defined career path for your team that places them on a road of growth and encouragement? Do you offer benefits and flexible work hours that meet their needs and goals? Maybe that is as simple as assisting with child care or offering flexible work hours.
Do you have a workflow that is well documented and includes a standardized set of tools, equipment and process? Do you onboard your new staff? Does your business look like the rest of today’s industry? Think about what I’ve started here. Please don’t take it personally, but consider its importance. What we are selling the youth of today isn’t attractive. We need a serious makeover and this article was intended to start that discussion. It’s time to look at other mountains for inspiration.
The 2135QTL-2 is the ultimate torque wrench counterpart. It delivers 780 foot-pounds of max reverse torque to remove stubborn lug nuts quickly and reaches target torque in two to three seconds. It weighs just 4.3 pounds to reduce fatigue with repeated use. The 2" anvil provides better access to recessed lug nuts, ideal for tire shops and service centers.
Built as a solution for all high roof cargo vans, the Max Rack 2.0 allows tradesmen easy access to their ladders with the least amount of effort. The loading and unloading process is a smooth, single stage operation that drops the ladder down to the right height, quickly and efficiently. By reducing the sweep angle of the rack handle by 45 degrees, it’s now even easier for tradesmen to operate the rack from the ground.
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RL-600 is a DOT 4 brake fluid engineered using a strict combination of Borate Esters and Glycol Ethers, in addition to specific moisture and corrosion inhibitors, for exceptional performance under any conditions. Brake fluids of all kinds are subject to moisture absorption throughout their lifecycles and that moisture can reduce the fluid’s wet boiling point, lowering its effectiveness. Red Line’s RL-600 combats this problem with its use of components which reduce moisture absorption.
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Full day technical training classes from ZF Aftermarket are slated to kick off next week at ZF Aftermarket’s Vernon Hills, IL location. This year’s training courses will cover modern chassis technologies as well as diagnostics for 6HP and 8HP transmissions. ZF technical trainers have designed engaging, customized programs that bring ZF’s OE expertise into the hands of technicians in the automotive aftermarket.
