ASE A1- ENGINE REPAIR 2025
EXAM
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
A single rod bearing shows excessive wear, but the rest show normal wear.
Technician A says this could be due to an out-of-round connecting rod bore.
Technician B says that this could be due to an obstruction in the crankshaft oil
passage(s) that supplies the bearing. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right. One rod bearing showing wear that is different than the rest could have an
obstruction in the crankshaft oil passage(s) that supplies the bearing or an out-of-
round rod bore.
QUESTION 2
All of the following could cause an engine to ping or detonate EXCEPT:
A. A faulty EGR valve
B. Retarded ignition timing
C. Excessive machining of the cylinder head
END OF
PAGE 1
, ASE A1- ENGINE REPAIR 2025
EXAM
D. Using fuel with too low of an octane rating - ANSWERS-The correct answer is
B. Ignition timing that is too far advanced would cause pinging or detonation, but
retarded ignition timing would not. Excessive cylinder head resurfacing would
raise compression and could cause pinging or detonation. An inoperative EGR
valve would let combustion chamber temperatures become too high and could
cause pinging or detonation. Fuel with too low an octane rating will burn too
quickly and can be ignited by hot spots in the combustion chamber.
QUESTION 3
Technician A says that a twisted connecting rod would cause a slanted wear pattern
on the side of a piston. Technician B says that a bent connecting rod would cause
the rod bearing inserts to have more wear on one side. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right.
QUESTION 4
Technician A says that a defective harmonic balancer can cause inaccurate ignition
timing readings. Technician B says that a defective harmonic balancer can cause a
broken crankshaft. Who is right?
END OF
PAGE 2
, ASE A1- ENGINE REPAIR 2025
EXAM
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right. The outer ring on a defective harmonic balancer can slip, causing inaccurate
ignition timing readings. A broken crankshaft can also result from an incorrect or
defective balancer.
QUESTION 5
Technician A says the flywheel on an externally balanced engine can only be
installed in one position on the crankshaft flange. Technician B says that flywheel
runout should be checked with a straightedge and feeler gauge. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is A. On externally balanced
engines, the flywheel must be correctly indexed when it is mounted on the
crankshaft to maintain engine balance (many flywheels have bolt holes that are
unevenly spaced so they can only go on one way). Make certain that index marks
are properly aligned when installing the flywheel. Runout on the face of the
flywheel is checked with a dial indicator.
END OF
PAGE 3
, ASE A1- ENGINE REPAIR 2025
EXAM
QUESTION 6
All of the following could cause an engine to overheat EXCEPT:
A. Defective fan clutch
B. Clogged cooling system
C. Broken fan shroud
D. Stuck open thermostat - ANSWERS-The correct answer is D. A thermostat that
is stuck open will not restrict coolant flow. A clogged cooling system would
restrict coolant flow and cause engine overheating. A defective fan clutch and
broken fan shroud would both reduce air flow through the radiator and could cause
engine overheating.
QUESTION 7
All of the following can cause an engine oil leak EXCEPT:
A. Cracked valve cover gasket
B. Stuck open PCV valve
C. Worn rear main seal
D. Worn piston rings - ANSWERS-The correct answer is B. A cracked valve cover
gasket and worn rear main seal would allow oil to leak past their damaged
surfaces. Worn piston rings would cause excessive crankcase pressure and push oil
past seals and gaskets that are in good condition. A stuck open PCV would not
END OF
PAGE 4
EXAM
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
A single rod bearing shows excessive wear, but the rest show normal wear.
Technician A says this could be due to an out-of-round connecting rod bore.
Technician B says that this could be due to an obstruction in the crankshaft oil
passage(s) that supplies the bearing. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right. One rod bearing showing wear that is different than the rest could have an
obstruction in the crankshaft oil passage(s) that supplies the bearing or an out-of-
round rod bore.
QUESTION 2
All of the following could cause an engine to ping or detonate EXCEPT:
A. A faulty EGR valve
B. Retarded ignition timing
C. Excessive machining of the cylinder head
END OF
PAGE 1
, ASE A1- ENGINE REPAIR 2025
EXAM
D. Using fuel with too low of an octane rating - ANSWERS-The correct answer is
B. Ignition timing that is too far advanced would cause pinging or detonation, but
retarded ignition timing would not. Excessive cylinder head resurfacing would
raise compression and could cause pinging or detonation. An inoperative EGR
valve would let combustion chamber temperatures become too high and could
cause pinging or detonation. Fuel with too low an octane rating will burn too
quickly and can be ignited by hot spots in the combustion chamber.
QUESTION 3
Technician A says that a twisted connecting rod would cause a slanted wear pattern
on the side of a piston. Technician B says that a bent connecting rod would cause
the rod bearing inserts to have more wear on one side. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right.
QUESTION 4
Technician A says that a defective harmonic balancer can cause inaccurate ignition
timing readings. Technician B says that a defective harmonic balancer can cause a
broken crankshaft. Who is right?
END OF
PAGE 2
, ASE A1- ENGINE REPAIR 2025
EXAM
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is C, both technicians are
right. The outer ring on a defective harmonic balancer can slip, causing inaccurate
ignition timing readings. A broken crankshaft can also result from an incorrect or
defective balancer.
QUESTION 5
Technician A says the flywheel on an externally balanced engine can only be
installed in one position on the crankshaft flange. Technician B says that flywheel
runout should be checked with a straightedge and feeler gauge. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANSWERS-The correct answer is A. On externally balanced
engines, the flywheel must be correctly indexed when it is mounted on the
crankshaft to maintain engine balance (many flywheels have bolt holes that are
unevenly spaced so they can only go on one way). Make certain that index marks
are properly aligned when installing the flywheel. Runout on the face of the
flywheel is checked with a dial indicator.
END OF
PAGE 3
, ASE A1- ENGINE REPAIR 2025
EXAM
QUESTION 6
All of the following could cause an engine to overheat EXCEPT:
A. Defective fan clutch
B. Clogged cooling system
C. Broken fan shroud
D. Stuck open thermostat - ANSWERS-The correct answer is D. A thermostat that
is stuck open will not restrict coolant flow. A clogged cooling system would
restrict coolant flow and cause engine overheating. A defective fan clutch and
broken fan shroud would both reduce air flow through the radiator and could cause
engine overheating.
QUESTION 7
All of the following can cause an engine oil leak EXCEPT:
A. Cracked valve cover gasket
B. Stuck open PCV valve
C. Worn rear main seal
D. Worn piston rings - ANSWERS-The correct answer is B. A cracked valve cover
gasket and worn rear main seal would allow oil to leak past their damaged
surfaces. Worn piston rings would cause excessive crankcase pressure and push oil
past seals and gaskets that are in good condition. A stuck open PCV would not
END OF
PAGE 4
