Technical Articles

By Andrew Markel. Join Andrew, a former technician and service writer, and uncover nine great tips you should consider when performing TPMS work. Find out how to create more revenue, boost productivity and best of all, reduce customer comebacks.

By Scott ‘Gonzo’ Weaver. Do you remember a time when we didn’t have a malfunction indicator light on the dash? If you do, then you would also remember the thick, heavy smog of California’s valley cities and the stench from an exhaust pipe while sitting at a traffic light. Technology and the family vehicle have come a long way from the days of belching high amounts of NOx, CO and HC out of the tailpipes.

By Gary Goms. Most of us working in the automotive service trades are very familiar with Murphy’s Law and how it affects our shop’s cost of doing business. Murphy’s Law says, “Everything that can go wrong usually will go wrong.”

By Gary Goms. During the past century, ignition coil configurations have evolved from oil-filled canister to epoxy-filled to e-core to waste spark and to the most modern coil-on-plug or “pencil” coils. Whatever the configuration, an ignition coil creates a spark by transforming amperage into volts.

By Frank Walker. As you may know, the air conditioning compressors in many hybrid vehicles are operated by an electric motor instead of a drive belt. The motor’s insulated windings are immersed in the compressor’s lubricating oil. The oils used in these compressors are formulated to have high dielectric properties, that makes them non-conductive.

By Scott ‘Gonzo’ Weaver. By the early 1990s, almost all import automotive manufacturers had a successful variable valve timing (VVT) system in production. These systems offered higher performance from smaller displacement engines at higher rpm. As these vehicles exceeded their new car warranties, technicians learned the ins and outs of these systems and how regular oil changes could increase the life of VVT components. Now, the VVT is playing a direct role in vehicle emissions and the way gases are burned in the combustion camber.

By Jim Piraino. Over the past couple of months, it has come to my attention that auto repair professionals are seeing a rise in the failure rate of the wheel sensors that supply the signal to Tire Pressure Management Systems (TPMS). Most of these failures are due to dead batteries, as each of the four sensors has a non-replaceable battery built into them. In most cases, these batteries have a life expectancy of 5 to 6 years. Although some upscale vehicles, such as BMW, have sophisticated systems that allow the technicians to monitor battery life as a percentage (using a scan tool), most will give no warning of pending failure. For the millions of vehicles rapidly approaching this 5 to 6 year age bracket, it’s not a question of if the sensor will fail, but rather when it will fail.

By Sergio Fernandez. Real-life repair scenario: 2003 E320, with 3.2L V6 engine and 120,000 miles. A customer brings his car into the shop with a “strange vibration.” After we scanned the vehicle, we found the following DTCs: P0305, misfire on cylinder #5; and P0301, misfire on cylinder #1.

By Scott ‘Gonzo’ Weaver. So many manufacturers are now running the brake lights through BCMs, Integrated Power Modules, bulb detection systems, or the anti-lock brakes. Along with just about every other system in today’s cars, computers are doing a lot of the work for us.

Check out the latest tech tip from Delphi. Take a look at the engine management system and common types of oxygen sensors and how they work, as well as common failures and faults.

For all 2012 model year vehicles, stability control is standard. For model year 2008, the majority of vehicles sold were sold with ABS and optional stability control. Most of these systems have something in common, sensors that measure the dynamics of the vehicle and the intentions of the driver.

By Andrew Markel. A smoke machine may seem like an expensive piece of equipment if it is just used for testing EVAP systems. But, if you factor in other diagnostic tests it can perform, it is a worthwhile investment. The following are 10 tests for smoke machines not involving the EVAP system.

By Andrew Markel. While there are many times where you will be able to repair a vehicle’s brakes without a scan tool, you only have to run into one car that needs this to make it worth having. The reality is that if your customer’s vehicle is 10 years old or newer, there’s nearly a 100% chance that you could need a scan tool to perform some sort of test/repair on the brake system.

By Andrew Markel. The overall response to the 7 Brake Myths Busted article was huge. I took a lot of abuse, but that was the goal of the article. Too many times technicians get stuck in a mindset that leads to false diagnoses. The point of the article was to shake things up in your diagnostic thinking.

By Andrew Markel. There are some myths about brake pads, rotors and hydraulics that need to be busted. These myths can hurt and hinder a technician’s ability to diagnose and solve some brake problems and customer concerns. On the surface, some of these myths make sense. The logic can seem sound and explain a problem, but they do not resolve the real issues with a brake system.

By Dave Hobbs. In addition to his work with Delphi, Dave Hobbs serves as an instructor for Indiana’s Ivy Tech Community College. He is also a frequent speaker at national training seminars, is a qualified hybrid instructor and writes for various industry magazines. Two decades of training engineers and service technicians around the world has provided Hobbs the unique ability to bridge the theoretical with the practical. Today, Hobbs talks with us about turbochargers and superchargers — what they are, how they run and what technicians can expect when servicing or installing these engine performance components.

By Kevin S. McCartney. Kevin McCartney has compiled this comprehensive list of information related to modern oil additive and supplements. This is sure to be an interesting read full of new information for anyone interested in the science behind modern automotive oils.

By Kevin S. McCartney. Modern engines rely much more heavily on the lubrication system for cooling than ever before. Oil coolers and coolant heated PCV systems present some new opportunities. But, there is a great deal of overlooked technology in modern motor oils that should be understood before this opportunity is addressed.

By Scott ‘Gonzo’ Weaver. Sometimes, I’ll find faults with the so called “experts” advice or information. Not that I think I’m smarter than the engineers… no, not that at all. But if something strikes me as not being completely correct I might want to question what is on that diagnostic tree. Mind you, my entire day is filled with meeting the expectations of my customers. I have to be dead on with my repairs and diagnostics. Not some of the time, no, ALL the time. And, I expect the same from the people that provide the information and parts. The way I look at it, you’re only as good as the information provided.

By Scott ‘Gonzo’ Weaver. When I was a kid, I used to watch my dad, who started out as a diesel mechanic, tune up cars and trucks from time to time. He would turn the adjustment screws on the carburetor until the engine smoothed out and started to purr. Then, after listening closely to the rumbling of the motor, the adjustment screws would get one final tweak. He would always bend down and cup his hand around the belching tail pipe exhaust and take a big sniff of the fumes, and then go back to his adjustments. That was back in the 60s and 70s before PCMs, O2 sensors and catalytic converters.

By Dave Hobbs. A climate control system that automatically maintains a set interior climate while conditions outside constantly change might seem complicated. Cool-headed diagnostics involve breaking these systems into manageable parts.

By Gary Goms. During the past nine months, I’ve had three instances of powertrain control module (PCM) failures on Jeep Wrangler vehicles that were evidently caused by an over-voltage condition. The first case involved an owner who requested that a local shop replace the fuel pump because his ’98 Wrangler was slow-starting in the morning.

By Scott ‘Gonzo’ Weaver. A customer comes into the shop the other day with a handful of papers about his car. Each page was full of information and diagrams pertaining to a repair. He was extremely proud of himself, and proceeded to tell me how he found this wealth of knowledge on the Internet.

By John Thornton. Last time (Fall 2010), we looked at two Nissan variable valve timing case studies, provided by John Thornton. There wasn’t enough room in that issue for John’s very informative third case study, so it’s included here. After we’ve finished with the third case study, we’ll move into an overview of the construction, operation and diagnosis of various crank sensor designs. Let’s get started.

By Scott ‘Gonzo’ Weaver. So, you’ve just finished up a Ford, and you’re about to try and start it up. However, it needs programmed. You’ve decided to use a J2534 tool, but there are certain things you’ll need to consider before purchasing that subscription at www.motorcraftservice.com.

By David Tenpenny. Everyone knows, or seems to know, that synthetic oils are better than conventional oils, but do you know why? The fact is synthetic oils have several material advantages over their non-synthetic counterparts. Synthetic oils are structured with very specific properties, which leads to stronger oxidative protection against breakdown and lower evaporation rates under high temperature conditions. Synthetics also excel at low temperature operation and provide superior film strength.

By Scott ‘Gonzo’ Weaver. Since 1998, all new cars have been required to have Supplemental Restraint Systems as standard equipment. A study done in December 2001 found that a record was set with 7,585 confirmed prevented deaths by proper airbag/seatbelt usage. If that isn’t enough to make you appreciate the airbag systems in today’s cars, I don’t know what will.

By Peter Coll. HFO-1234yf, a new replacement for R-134a, is a non-environmental impact refrigerant with a decreased atmospheric lifetime. Learn what it is, why we’re changing refrigerants, what the differences are, whether or not your shop will need new equipment, and more, in this question-and-answer session with Peter Coll from Neutronics.

By Scott ‘Gonzo’ Weaver. Leave it to the manufacturers to take a simple thing like heat and air conditioning and turn it into an electronic jungle of wiring, sensors, and computer components. HVAC units have come a long way from when I started in the business. Not that I want to dwell on the past, but it might be a good idea to make sure we understand the basics before diving into the problem of today’s systems. I always feel that if I understand a system fully before doing any repair work I’m more likely to get it right the first time.

By Gary Goms. Although diagnosing misfires can be a tough assignment for any driveability technician, the diagnosis can be made much simpler if he understands the basics of misfire diagnosis. For example, when the first OBD II misfire monitor was first introduced in 1996, technicians were puzzled by problems with false misfire diagnostic trouble codes (DTCs). Case in point, vehicles being driven on washboard dirt roads began recording false misfires.

By Joe Glassford. Accuracy of: Plus or minus 0.1% is Best. Check the owner’s manual for your meter under DC accuracy.

By Carlton Banks. Many modern-day fuel systems offer a new look into system status definitions. It’s become very important to extend our understanding well beyond the concepts of simple “open loop” and “closed loop” status. This month, we will explore the new fuel system definitions that are present on many of today’s vehicles. We’ll begin our discussion by looking at each one on an individual basis.

By Scott ‘Gonzo’ Weaver. Some male patrons tend to want to “talk to the mechanic” verses talking to the front-desk person. Especially if that person is female. In my case, the front desk person is my daughter. She has seen it all and is very knowledgeable, I might add. Ask her a car question, any question, and she’ll have an answer for you.

By Joe Glassford. In this excerpt from Joe Glassford’s new Vehicle Testing Reference Guide Joe details a technique on how to easily test a wire without piercing it. Don’t want to pierce or cut wires, or if you have a completely molded connector where it seems impossible to get an acupuncture probe tool in for your testing try this out.

By Gary Goms. This real-world case study of a 2002 Chevy S-10 pickup, a 1995 Buick and a 1995 Lincoln Town Car illustrates why “chasing” trouble codes can get you lost in the Diagnostic Woods. Working as a part-time mobile diagnostic technician, I find that many techs find themselves “lost in the woods” while diagnosing engine management system failures. Although not perfect, the “lost in the woods” analogy describes the dilemma of a technician through a forest of information without a good sense of direction. Unfortunately, most of us have found ourselves in that situation more often than we would like to admit.