ASE 1 - Engine Performance Questions
and Answers Already Passed
2. A technician is checking for piston ring groove clearance. The proper technique includes
A. The old ring and a feeler gauge.
B. The new ring and a feeler gauge.
C. Only a feeler gauge.
D. No feeler gauge is required. ✔✔Answer B is correct. Clean the pistons in a cold tank and
then clean the grooves with a ring groove cleaner before measuring.
3. A cylinder power balance test is being performed on a vehicle with sequential fuel injection.
The number five cylinder's rpm drop is less than all of the others. Technician A says this could
be the result of a restriction in the fuel injector. Technician B says this could be caused by
leaking secondary insulation. Who is correct?
A. Technician A
B. Technician B
C. Both A and B
D. Neither A or B ✔✔Answer C is correct. Both restricted fuel injectors and leaking secondary
wires will reduce the cylinder's contribution. Anything that would have an affect on the
,cylinder's power. It could be mechanical like a faulty valve, possibly the ignition, or the fuel
mixture affecting this cylinder's power output.
4. A turbocharger wastegate is sticking. Technician A says a stuck open wastegate will result in
overboost. Technician B says a stuck closed wastegate will result in an underboost condition.
Who is correct? ✔✔Neither technician is correct.
5. Technician A says a supercharger uses an intercooler to keep the engine's oil cool. Technician
B says intercoolers are used on turbochargers to keep the oil cool. Who is correct? ✔✔Neither
technician is correct.
6. A wet compression test is being performed on a four cylinder engine. The number two
cylinder's compression is below specifications and remains the same after injecting oil. This
result indicates:
A. Worn piston rings.
B. A faulty valve.
C. A hole in the piston.
D. Excessive carbon buildup on the piston's dome. ✔✔Answer A is wrong. If compression
increases after injecting oil into the chamber, the piston rings are worn. This is because the oil
fills the gap caused by the worn rings increasing the cylinder's compression.
,Answer B is correct. If there is no change in compression after adding oil, the cylinder has a
faulty head gasket or valve.
7. A vehicle has blue colored exhaust. Technician A says this may be caused by weak piston
rings. Technician B says this may be caused by a leaking fuel injector. Who is correct?
A. Technician A
B. Technician B
C. Both A and B
D. Neither A or B ✔✔Answer A is correct. Oil is burning in the combustion chamber causing
blue colored exhaust.
8. Technician A says to remove the ridge on the engine block before removing the pistons.
Technician B says a block's ridge will damage the new piston rings during installation. Who is
correct?
A. Technician A
B. Technician B
C. Both A and B
, D. Neither A or B ✔✔Answer C is correct. Remove the damaging ridge with a ridge reamer
before removing pistons. This also prevents damage to the new piston rings when it comes time
to reinstall the pistons.
9. A vehicle briefly blows blue/gray smoke from the tailpipe when it's first started in the
morning. The MOST likely cause of this condition is a:
A. Worn piston ring.
B. Lean fuel condition.
C. Leaking fuel injector.
D. Leaking valve seal. ✔✔Answer A is wrong. Worn piston rings would result in blue/gray
smoke at all times, not just in the mornings.
Answer B is wrong. Both a rich and a lean fuel condition will result in excessive HC's in the
emissions.
Answer C is wrong. A rich fuel condition will result in black smoke emitting from the tailpipe.
Answer D is correct. A leaking valve seal will cause oil to leak into the cylinder's chamber over
time, usually overnight.
10. During a cylinder leakage test air bubbles appear in the neck of the radiator. Technician A
says a faulty intake valve will cause this condition. Technician B says a crack in the engine block
will cause this condition. Who is correct?
and Answers Already Passed
2. A technician is checking for piston ring groove clearance. The proper technique includes
A. The old ring and a feeler gauge.
B. The new ring and a feeler gauge.
C. Only a feeler gauge.
D. No feeler gauge is required. ✔✔Answer B is correct. Clean the pistons in a cold tank and
then clean the grooves with a ring groove cleaner before measuring.
3. A cylinder power balance test is being performed on a vehicle with sequential fuel injection.
The number five cylinder's rpm drop is less than all of the others. Technician A says this could
be the result of a restriction in the fuel injector. Technician B says this could be caused by
leaking secondary insulation. Who is correct?
A. Technician A
B. Technician B
C. Both A and B
D. Neither A or B ✔✔Answer C is correct. Both restricted fuel injectors and leaking secondary
wires will reduce the cylinder's contribution. Anything that would have an affect on the
,cylinder's power. It could be mechanical like a faulty valve, possibly the ignition, or the fuel
mixture affecting this cylinder's power output.
4. A turbocharger wastegate is sticking. Technician A says a stuck open wastegate will result in
overboost. Technician B says a stuck closed wastegate will result in an underboost condition.
Who is correct? ✔✔Neither technician is correct.
5. Technician A says a supercharger uses an intercooler to keep the engine's oil cool. Technician
B says intercoolers are used on turbochargers to keep the oil cool. Who is correct? ✔✔Neither
technician is correct.
6. A wet compression test is being performed on a four cylinder engine. The number two
cylinder's compression is below specifications and remains the same after injecting oil. This
result indicates:
A. Worn piston rings.
B. A faulty valve.
C. A hole in the piston.
D. Excessive carbon buildup on the piston's dome. ✔✔Answer A is wrong. If compression
increases after injecting oil into the chamber, the piston rings are worn. This is because the oil
fills the gap caused by the worn rings increasing the cylinder's compression.
,Answer B is correct. If there is no change in compression after adding oil, the cylinder has a
faulty head gasket or valve.
7. A vehicle has blue colored exhaust. Technician A says this may be caused by weak piston
rings. Technician B says this may be caused by a leaking fuel injector. Who is correct?
A. Technician A
B. Technician B
C. Both A and B
D. Neither A or B ✔✔Answer A is correct. Oil is burning in the combustion chamber causing
blue colored exhaust.
8. Technician A says to remove the ridge on the engine block before removing the pistons.
Technician B says a block's ridge will damage the new piston rings during installation. Who is
correct?
A. Technician A
B. Technician B
C. Both A and B
, D. Neither A or B ✔✔Answer C is correct. Remove the damaging ridge with a ridge reamer
before removing pistons. This also prevents damage to the new piston rings when it comes time
to reinstall the pistons.
9. A vehicle briefly blows blue/gray smoke from the tailpipe when it's first started in the
morning. The MOST likely cause of this condition is a:
A. Worn piston ring.
B. Lean fuel condition.
C. Leaking fuel injector.
D. Leaking valve seal. ✔✔Answer A is wrong. Worn piston rings would result in blue/gray
smoke at all times, not just in the mornings.
Answer B is wrong. Both a rich and a lean fuel condition will result in excessive HC's in the
emissions.
Answer C is wrong. A rich fuel condition will result in black smoke emitting from the tailpipe.
Answer D is correct. A leaking valve seal will cause oil to leak into the cylinder's chamber over
time, usually overnight.
10. During a cylinder leakage test air bubbles appear in the neck of the radiator. Technician A
says a faulty intake valve will cause this condition. Technician B says a crack in the engine block
will cause this condition. Who is correct?
