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Do You Survey Your Customers, and How?

Recently, I had the opportunity to take my car to a body shop (it’s a long story). Once the work was done and I was checking out, the office manager mentioned to me that they would be sending me a customer satisfaction survey and encouraged me to fill it out. Then she...

Interpreting Compression Tests–ASE Practice Questions (VIDEO)

Description Technician A has just completed a running compression test using a mechanical compression gauge. Technician B says that the test is used to check the volumetric efficiency of the engine. Technician A says that the higher-than-expected readings indicate a...

Do I Need a Tune-up?

If you’re like me, you might cringe a little. More often than not, they’re hoping this magical procedure will fix some mysterious issue with their car. But let’s break it down: what is a tune-up, anyway? Most dictionaries describe a tune-up as “a general adjustment to...

PSA: Be Safe With Brake Cleaner

If you work in a shop (and if you’re reading this, chances are you do), you are undoubtedly familiar with brake cleaner. And, if you know the scent of brake cleaner, you probably know that using it is not great for your health if it comes in contact with your skin,...

When a Voltmeter Isn’t Enough (Video)

Description With the variety of electronically controlled systems on a modern automobile, the days when a test light or simple voltmeter was enough to diagnose problems are long gone. Using a digital storage oscilloscope (DSO) can make troubleshooting faster and more...

P0420/P0430—The #1 DTC in the Country

DTCs (Diagnostic Trouble Codes) P0420 and P0430 are generic industry codes and part of the OBD-II standards. The descriptor labels the code(s) “Catalytic Converter Efficiency Below Threshold – Bank 1 (or 2)”. And the number one part sold to repair this problem is a...

Compression Testing | ASE Practice Questions (VIDEO)

by | Aug 12, 2025

1 comment

Description

Technician A has just completed a dry compression test of a four-cylinder engine. All four cylinders are below specification by about the same amount. After performing a wet compression test, values remained unchanged.

What could cause this condition?
A) Exhaust restriction
B) Cam/crank timing out of specification
C) Worn piston rings
D) Leaking intake valves

Related Videos

Troubleshooting Fuel Trim–ASE Practice Questions (VIDEO)

by | Jul 29, 2025

Technician A and Technician B are discussing ways to use fuel trim as a troubleshooting aid. Technician A says that fuel trims that are correcting for a lean condition at high RPM and load conditions indicates a problem in fuel delivery. Technician B says that this condition is caused by a vacuum leak.

Misfire Cause–ASE Practice Questions (VIDEO)

by | Jul 15, 2025

Technician A is diagnosing a misfire. He states that a misfire is caused by a fault in the ignition system and that new plugs and coils will repair the problem. Technician B says that a misfire is detected when the ECM detects a variation in crankshaft speed.

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