ASE-A8 Engine Performance Exam Questions and
Answers.
1. What does a wet compression test, test for? - Correct Answer Burned valve would show
no change in compression.
A leaking/worn piston would have some change in compression.
What most likely is the cause if the compression doesn't go up during a wet compression
test?
A, burnt valve.
B, worn piston ring. - Correct Answer A
What most likely is the cause if the compression goes up during a wet compression test?
A, burnt valve.
B, worn piston ring. - Correct Answer B
2. Blue smoke is coming from the exhaust pipe of a vehicle, what most likely is the cause?
A, worn piston ring.
B, bad head gasket. - Correct Answer A
3. A vacuum guage is connected to the intake manifold of an engine and the engine is run
at 2000 rpm. During the test, the pointer on the guage fluctuates rapidly between readings
of 10 and 20 inches of vacuum. These test results point to:
A, a leaking intake manifold.
B, worn piston rings.
C, worn valve guides.
D, a week or broken valve spring. - Correct Answer D, a weak or broken valve spring
would cause a vacuum guage to fluctuate or jump from high to low readings.
4. Engine detonation (knock) could be caused by any of the following Except:
,A. a lean air/fuel mixture
B. retarded ignition timing
C. excess carbon in the the combustion chambers
D. a stuck-closed EGR valve - Correct Answer B. Advanced ignition timing will cause a
knock, but retarded timing will not.
5. A vehicle with electronic ignition hesitates and stumbles during acceleration. The
problem goes away when the vacuum advance hose is disconnected and plugged.
Technician A says that a stuck vacuum advance mechanism could be the cause.
Technician B says that an intermittent open in the pickup coil leads could be the cause.
Who is right?
A. Technician A only
B. Technician B only
C. Both A and b
D. Neither A or B - Correct Answer B. If a vacuum advance mechanism were stuck, the
problem would not change if the vacuum hose is connected or disconnected. When the
vacuum changes to the vacuum advance mechanism and the distributor plate moves, this
may move the wires to the pick-up causing a short or open which would cause the pick-up
signal to be lost momentarily.
6. Technician A says that spark advance on and engine can be tested by listening to the
way the engine sounds at higher rpms. Technician B says that spark advance on an
engine can be tested with a timing light that incorporates an ignition advance meter. Who
is right.
A. Technician A only
B. Technician B only
C. Both A and B
D. Nether A or B - Correct Answer B. to accurately measure spark advance use a timing
light. The spark advance cannon be determined by listening to the way the engine sounds.
7. A regular customer presents his vehicle for service. He describes symptoms of poor
drive ability and says that the vehicle has been repaired for the same problem in the past.
Which of the following you should do first?
A. connect the vehicle to an engine analyzer
, B. check for diagnostic trouble codes.
C. check the vehicle service history and check for TSBs, service campaigns and recalls
D. perform a cylinder balance test - Correct Answer C. Checking vehicle service history
would point you in the right direction.
8. Two Technicians are listening to a tapping noise coming from the top end of a v8
engine. Technician A says the noise could be a valve needing adjustment. Technician B
says the the noise could be an exhaust leak. who's is right?
A. Technician A only.
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer C. A tapping noise that doesn't go away after engine
warm up could be caused by worn valvetrain components or excessive valvetrain
clearance. A similar type of noise would be cause by and exhaust leaks the exhaust
manifold/cylinder head junction.
9. Technician A says a high spike line on an oscilloscope indicates a disconnected or
open plug wire. Technician B says a high spike line on an oscilloscope indicates a closed
gap on a spark plug. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer A. If a spark plug gap were closed, the oscilloscope
would indicate a very low spike line.
10. A vehicle can be started with great difficulty, but lacks power, and will not idle.
Technician A says says that there could be hole or a tear in the duct between the mass air
flow sensor and the throttle body. Technician B says that a restricted fuel filter is the
problem. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer A. a fuel filter would not be the cause of the problem
Answers.
1. What does a wet compression test, test for? - Correct Answer Burned valve would show
no change in compression.
A leaking/worn piston would have some change in compression.
What most likely is the cause if the compression doesn't go up during a wet compression
test?
A, burnt valve.
B, worn piston ring. - Correct Answer A
What most likely is the cause if the compression goes up during a wet compression test?
A, burnt valve.
B, worn piston ring. - Correct Answer B
2. Blue smoke is coming from the exhaust pipe of a vehicle, what most likely is the cause?
A, worn piston ring.
B, bad head gasket. - Correct Answer A
3. A vacuum guage is connected to the intake manifold of an engine and the engine is run
at 2000 rpm. During the test, the pointer on the guage fluctuates rapidly between readings
of 10 and 20 inches of vacuum. These test results point to:
A, a leaking intake manifold.
B, worn piston rings.
C, worn valve guides.
D, a week or broken valve spring. - Correct Answer D, a weak or broken valve spring
would cause a vacuum guage to fluctuate or jump from high to low readings.
4. Engine detonation (knock) could be caused by any of the following Except:
,A. a lean air/fuel mixture
B. retarded ignition timing
C. excess carbon in the the combustion chambers
D. a stuck-closed EGR valve - Correct Answer B. Advanced ignition timing will cause a
knock, but retarded timing will not.
5. A vehicle with electronic ignition hesitates and stumbles during acceleration. The
problem goes away when the vacuum advance hose is disconnected and plugged.
Technician A says that a stuck vacuum advance mechanism could be the cause.
Technician B says that an intermittent open in the pickup coil leads could be the cause.
Who is right?
A. Technician A only
B. Technician B only
C. Both A and b
D. Neither A or B - Correct Answer B. If a vacuum advance mechanism were stuck, the
problem would not change if the vacuum hose is connected or disconnected. When the
vacuum changes to the vacuum advance mechanism and the distributor plate moves, this
may move the wires to the pick-up causing a short or open which would cause the pick-up
signal to be lost momentarily.
6. Technician A says that spark advance on and engine can be tested by listening to the
way the engine sounds at higher rpms. Technician B says that spark advance on an
engine can be tested with a timing light that incorporates an ignition advance meter. Who
is right.
A. Technician A only
B. Technician B only
C. Both A and B
D. Nether A or B - Correct Answer B. to accurately measure spark advance use a timing
light. The spark advance cannon be determined by listening to the way the engine sounds.
7. A regular customer presents his vehicle for service. He describes symptoms of poor
drive ability and says that the vehicle has been repaired for the same problem in the past.
Which of the following you should do first?
A. connect the vehicle to an engine analyzer
, B. check for diagnostic trouble codes.
C. check the vehicle service history and check for TSBs, service campaigns and recalls
D. perform a cylinder balance test - Correct Answer C. Checking vehicle service history
would point you in the right direction.
8. Two Technicians are listening to a tapping noise coming from the top end of a v8
engine. Technician A says the noise could be a valve needing adjustment. Technician B
says the the noise could be an exhaust leak. who's is right?
A. Technician A only.
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer C. A tapping noise that doesn't go away after engine
warm up could be caused by worn valvetrain components or excessive valvetrain
clearance. A similar type of noise would be cause by and exhaust leaks the exhaust
manifold/cylinder head junction.
9. Technician A says a high spike line on an oscilloscope indicates a disconnected or
open plug wire. Technician B says a high spike line on an oscilloscope indicates a closed
gap on a spark plug. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer A. If a spark plug gap were closed, the oscilloscope
would indicate a very low spike line.
10. A vehicle can be started with great difficulty, but lacks power, and will not idle.
Technician A says says that there could be hole or a tear in the duct between the mass air
flow sensor and the throttle body. Technician B says that a restricted fuel filter is the
problem. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Correct Answer A. a fuel filter would not be the cause of the problem
