ASE Engine Repair and Performance 2

Question 1

A cylinder leakage test shows 30% leakage on cylinder 3, and air can be heard escaping from the oil fill cap. What is the most likely cause?

Accepted Answer

Worn piston rings or cylinder wall

Answer

Air escaping through the crankcase (oil fill or PCV) indicates leakage past the piston rings.

Question 2

During a cylinder leakage test, air is heard escaping from the throttle body. Which component is most likely at fault?

Accepted Answer

Intake valve

Answer

Air exiting through the intake system means the intake valve is not sealing.

Question 3

A wet compression test raises a low cylinder reading significantly. What does this indicate?

Accepted Answer

Worn piston rings

Answer

Oil temporarily seals worn rings, so compression rises when rings are the problem.

Question 4

An engine vacuum gauge reading fluctuates rhythmically between 14 and 18 in. Hg at idle. Technician A says this can indicate a burned or sticking valve. Technician B says it indicates a restricted exhaust. Who is correct?

Accepted Answer

Technician A only

Answer

A regular rhythmic drop points to a valve problem, while exhaust restriction causes vacuum to slowly fall with rpm.

Question 5

Which tool is used to measure cylinder bore taper and out-of-round?

Accepted Answer

Dial bore gauge

Answer

A dial bore gauge measures bore diameter at multiple points to determine taper and out-of-round.

ASE - Automotive Service Excellence Certified Tech Practice Test

ASE - Automotive Service Excellence Certified Tech Practice Test

ASE Engine Repair and Performance 2