Tech Tip: What Really Wears Out Inside Shocks and Struts
When shocks and struts wear out there are almost no visual clues. When a unit is leaking, it is a sign of failure and not wear. Next to performing an autopsy or throwing the unit on a dynamometer, there is no conclusive way to determine if the internal components are worn to a point where it could compromise vehicle stability. Even the “knee on the bumper” test can give false results due to how some units handle low frequency movements.
Undercar Repairs on 1996 to 2005 Volkswagens and Audis
Just as we get used to the types of powertrain, suspension, brake and exhaust systems that are coming into the marketplace, something different comes along. In this article, I’ll take a look at the designs and repair of the suspension, brake and exhaust systems of Volkswagens and Audis from 1996 to 2005. I won’t be able to cover everything in this article, just some of the highlights of the various models.
Diagnostic Dilemmas: Solving No-Code Performance Complaints
For many diagnostic techs, nothing is more discouraging and time-consuming than dealing with a no-code driveability complaint. Today’s second-generation On-Board Diagnostics II (OBD II) can be extremely sophisticated because the OBD II powertrain control modules (PCMs) in modern vehicles have far more computing capacity than did the older, pre-1996 OBD I vehicles. Nevertheless, we occasionally have to deal with a no-code performance complaint on a modern OBD II vehicle.
Solving Common Honda Driveability Problems
One of the common check engine light problems you’ll encounter on Hondas is a misfire code with no apparent misfire. Many times, this problem will be traced back to tight valve lash. Obviously, a tight valve will pass the audible test every time. But, it’s the tight valves that will set the check engine light in the best case, and if it’s ignored long enough you’ll be looking at a low-compression situation caused by a burnt valve.
Troubleshooting Wideband O2 Sensors
Many late-model imports such as Honda, Toyota, Volkswagen and others use Air/Fuel sensors rather than conventional oxygen sensors to monitor the exhaust gases coming out of the engine. What’s the difference? An air/fuel sensor can read a much wider and leaner range of fuel mixtures than a conventional O2 sensor. That’s why they’re also called “wideband” O2 sensors.
Tech Feature: BMW Diagnosing Electronic Accessories
BMW has some of the most technologically
Brake Job: 2007 GM Full-Sized 1500 Pick-Up and SUV
The GMT 900 debuted in 2007 as the replacement for the GMT 800. The first GMT 900 vehicle was the Chevrolet Tahoe, which arrived at dealers in January 2006. The GMC Yukon (regular and Denali) and Cadillac Escalade soon followed. Chevrolet Avalanches and Suburbans, GMC Yukon XLs, and Cadillac Escalade ESV and EXT were next to hit the roads.
Crankshaft and Camshaft Position Sensor Diagnosis
Nothing is more frustrating than diagnosing an intermittent cranking, no-start complaint with no diagnostic trouble codes (DTCs) and no apparent failure pattern. Much of the time, the cranking, no-start complaint lies with a failing crankshaft or camshaft position sensor. Many of these failures can be heat-related and might require several warm-up cycles to duplicate.
Tech Feature: Hemisphere Exploration – Journey to the Center of the 5.7L Hemi
The 5.7L HEMI Magnum V8, which made its debut in 2003 in Dodge Ram 2500/3500 series trucks, was quite an improvement over the older 5.9L V8 it replaced. The engine was 56 lbs. lighter, produced 41% more horsepower and 12% more torque than the previous motor. Better yet, it also delivered 8-10% better fuel economy.
Brake Pad Bedding – Adding a Little Seasoning to the Rotor
One of the most controversial topics involving brake repair is where noise comes from and what can be done to prevent it. All brake noise starts at the point where the pad and rotor make contact. Every squeak, chirp and groan has its origins at the interface between these two components and how it is expressed through the rest of the car.
Tech Feature: The DeLorean – Back From the Past
The DeLorean was often referred to as “the ethical sports car,” leading to the relatively small V6 engine and stainless-over-fiberglass construction with good fuel economy and long life in mind.
Tech Feature: General Motor’s Ecotec 2.0L Turbo Engine
General Motors introduced its powerful Ecotec 2.0L direct