Pulling Codes: Hit or Miss? Part III
In the first two articles, we looked at cranking compression and tailpipe analysis. We will now explore in-cylinder analysis. In order to have an understanding of this concept, one must envision the four-stroke cycle at the time the plug fires as a reference. This denotes the end of our compression stroke, and the beginning of the power stroke for that cylinder.
VW/Audi Maintenance that Drives Profits
To say that Volkswagen and Audi Group (sometimes mistakenly referred to as VAG) is a large part of the automotive scene worldwide is a gross understatement. From basic transportation to record-setting performance cars, VAG is a recognized leader in innovation and cutting-edge technology. A broad spectrum of models has put a huge number (millions) of VAG models on the road in North America, and these cars will provide many years of potential repair and service opportunities. Getting to know the various models, repair techniques and a few shortcuts will help make repairs more routine and profitable.
Tech Feature: Toyota V8 Timing Belt Service
When I first started researching this article, I called and stopped by several shops that do work on Toyota vehicles. I asked if any of them had any V8 models coming in for timing belts so I could get some pictures of the process. Either a blank stare, or a question like: “What Toyota V8?” was the general response. The idea that there was a Toyota V8 needing a timing belt replacement seems to be generally unknown in the aftermarket.
Wrangling in Jeep Spark Timing Dilemmas
Every once in a while I get a Diagnostic Dilemma that takes me back to the basics of how modern engine management systems work. This month’s happened to be a 1992 Jeep Wrangler equipped with the 4.0L engine and manual transmission. Of course, a vehicle of this vintage and configuration has to be about as basic as modern technology can get, right? Well, there are always exceptions.
Service Solutions: Lessons Learned Regarding ‘Old School’ Ignition Diagnosis
Recently, I’ve been confronted with driveability complaints on older vehicles that appear to defy conventional wisdom. Diagnosing such problems usually forces me to re-examine the fundamentals of engine
Timely Timing Chain Service: ‘Advancing’ Your Position in the Market
Timing chains and gears are engine parts that are usually replaced when an engine is rebuilt or when it has reached a high mileage total. Over time, gear teeth wear and chains stretch. This can cause noise, retarded valve timing (and ignition timing if the engine also has a cam-driven distributor), and a noticeable loss of performance and fuel economy.
Tech Tip: Kia Optima’s MIL Is On With DTC P0123 Set
This bulletin provides information relating to an engine hesitation or the illumination of the Malfunction Indicator Lamp (MIL) for P0123 (Throttle Position Sensor/Switch “A” Circuit High Input). Improper throttle position sensor (TPS) values may cause the engine to hesitate under loads or cause the illumination of the MIL. To correct this condition, the TPS has been improved.
Tech Feature: Diagnosing Automotive Lab Scope Dilemmas
Although digital storage oscilloscopes or “lab scopes” have now become standard equipment for most modern automotive repair shops, they still possess a mystique that tends to intimidate many technicians. Right off the top, a lab scope is basically a voltmeter that displays voltage signals along a time base. The vertical scale measures the amplitude or amount of the voltage and the horizontal scale measures an incremental time line along which the signals are displayed.
Tech Tip: Installing Timing Belt Covers with Guides for 2001 Hyundai Sonata, Santa Fe
Some 2001 Hyundai Sonata and Santa Fe vehicles may experience rough running, rough idle, lack of power at low rpm, or
the check engine light on. This may be caused by the exhaust camshaft coming out of time, which can be fixed by installing a new timing belt cover.
Tech Tip: Shim Calms Chirping Noises in Honda Models
Some Honda owners may complain of a chirp from the lower timing belt area. The noise is most often noticed at idle, usually after the engine has warmed up. The probable cause is the idler pulley mounting surface is tilted, causing the edge of the timing belt to rub against the side of the pulser flange on the drive pulley (gear).
Tech Tip: Honda’s V6 Engine Leaks Oil from Front/Middle/Rear
If oil is leaking from the front, middle or rear of one of the above engines, it may be due to the cast aluminum engine block may be porous in spots. Depending on the location of the leak, seal it with JB Weld or 3-Bond-coated sealing bolts.
Tech Feature: Valve Timing Terror Tales
While a lot has been written about timing belt replacement intervals, not a lot has been written about diagnosing timing belt and valve timing-related driveability complaints. In this article, Gary Goms reports that he is beginning to see more driveability problems caused by faulty valve timing.