Gary Goms, Author at UnderhoodService - Page 20 of 25
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Diagnostic Solutions: Oxygen Sensor Diagnostics

Once considered leading-edge technology, today’s oxygen sensor has become a commonplace service item on modern vehicles. Popularly introduced in the 1970s, the Lambda or, as it’s more popularly known, the oxygen sensor, rapidly became standard equipment as it’s a vital component of closed-loop or feedback fuel control technology. By using a voltage input from the

Component Connection: The Circle of (Engine) Life

Amazingly, up to a third of the heat energy produced inside an engine’s combustion chambers ends up as waste heat that goes into the block. This heat must be eliminated, otherwise the engine will overheat and self-destruct. The water pump keeps coolant circulating between the engine and radiator to get rid of the heat. The

Diagnostic Solutions, Servicing Filters: Top-Notch Design Is Key When Selecting New Filters

Veteran auto mechanics well remember the days of oil-bath air filters, cartridge-type oil filters, and sediment-bowl fuel filters. While these early-design filters would work well under a narrow range of circumstances, most were woefully inefficient and inadequate in the long term. All were subject to careless installation and dirt contamination during servicing. As disposable “paper”

Selling Services: Providing Manual Transmission Clutch Replacement Service

Because a good “stick shift” driver can always squeeze a few more miles per gallon out of a manual transmission or otherwise out-perform their automatic transmission counterparts, it’s no wonder that clutch replacements continue to be a good business for repair shops. In most cases, a routine clutch replacement requires very little in special tooling

Diagnostic Dilemmas: The Pressures of Intake Manifold Vacuum Tests

Several years ago, a retired school teacher brought in a 1994 Chevrolet S-10 Blazer that had developed an intermittent rough idle condition. Although a rebuilt engine had been installed a year before, and all of the wiring and vacuum hoses looked as if they were in factory condition, I took nothing for granted. An ignition

Master Cylinder Inspection

Although the mechanics of modern master cylinders seem deceptively simple, today’s dual-piston or tandem master cylinders still require the utmost in care and attention to maintain safe, reliable operation. The tandem master cylinder contains two piston assemblies; one for each axle set or diagonally located pair of brakes. Each piston assembly has two lip seals

Diagnostic Solutions: Throttle Position Sensors

Although conventional throttle position sensors attached to the throttle shaft are considered basic technology on modern engine management systems, the conventional throttle sensor plays an important role in its relationship with other sensors. The voltage inputs of most throttle position (TP) sensors may, for example, be coordinated with the barometric pressure (BARO), manifold absolute pressure

Diagnostic Solutions: Reading Spark Plugs Is As Much An Art As It Is A Science

Barring mechanical contact between the spark plug and piston, just about any randomly selected spark plug will ignite the gasoline and air compressed into an engine’s combustion chamber. Very few spark plugs, however, will continue to perform well under a wide range of engine temperatures, loads and speeds, not to mention lasting well beyond today’s

Diagnostic Dilemmas: Internal Engine Diagnostics

The nuts and bolts of measuring cylinder leakage In OBD II diagnostics, most of us know that an external component like a faulty fuel injector, ignition coil, spark plug or spark plug wire is usually responsible for a P0300-series cylinder misfire trouble code. Nevertheless, even with more sophisticated onboard diagnostic strategies, the PCM usually can’t

Diagnostic Solutions: Wheel Bearing Diagnosis

PROPER PROCEDURES AND CORRECT TOOLS PREVENT COMEBACKS Although wheel bearings are often the most neglected part of the vehicle, they nevertheless have a critical job to do, and in most cases, do it very well. Not only are wheel bearings designed to support the weight of the vehicle and allow it to travel over a

Talking Shop: Training Challenges Every Shop Faces

Your technicians are acquiring training. But are they getting the right type of training? This month, a repair shop owner and renowned columnist offers his opinion on the subject. Although shop owners are routinely encouraged by industry leaders to provide from 40 to more than 100 hours per year training for each technician, some shop