ASE A1 (ENGINE REPAIR) PRACTICE
TEST – CUMULATIVE CERTIFICATION
SCRIPT 2026 QUESTIONS WITH
SOLUTIONS GRADED A+
◍ A compression test shows that one cylinder is too low. A leakage test on that
cylinder shows that there is excessive leakage. During the test, air could be
heard coming from the tailpipe. Which of the following could be the cause?.
Answer: An exhaust valve not seating - If an exhaust valve is not seating, air
will leak from the combustion chamber by way of the valve out to the
tailpipe and make an audible sound. Broken rings or a bad head gasket
would have air leaking through the oil filler or cooling system.
◍ A compression test shows that one cylinder is too low. A leakage test on that
cylinder shows that there is excessive leakage. During the test, air could be
heard coming from the tailpipe. Which of the following could be the cause?
A. Broken piston rings
B. Bad head gasket
C. Bad exhaust gasket
D. An exhaust valve not seating.
Answer: The correct answer is D. If an exhaust valve is not seating, air will
leak from the combustion chamber by way of the valve out to the tailpipe
and make an audible sound. Broken rings or a bad head gasket would have
air leaking through the oil filler or cooling system.
◍ Technician A says that main bearing oil clearance can be checked with
Plastigauge. Technician B says that main bearing oil clearance can be
checked with dial bore gauge. Who is right?.
Answer: Both A and B - Either method can be used to check main bearing
, oil clearance.
◍ Technician A says that main bearing oil clearance can be checked with
plastigage. Technician B says that main bearing oil clearance can be
checked with a dial bore gauge. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B.
Answer: The correct answer is C, both technicians are right. Either method
can be used to check main bearing oil clearance.
◍ Which of the following is NOT a method of correcting excessive valve
stem-to-guide clearance?
A. Knurling the valve stem
B. Knurling the guide
C. Reaming for oversize
D. Guide replacement.
Answer: The correct answer is A. The valve stem is hardened and cannot be
knurled.
◍ Which is NOT a method of correcting excessive valve stem-to-guide
clearance?.
Answer: Knurling the valve stem - The valve stem is hardened and cannot
be knurled.
◍ A vacuum gauge is connected to the intake manifold of an engine running at
idle. The pointer on the gauge fluctuates rapidly but steadies as the engine
speed is increased. The test results indicate:
A. A leaking intake manifold gasket
B. Worn valve guides
C. Late ignition timing
D. A weak valve spring.
Answer: The correct answer is B. Worn valve guide could cause the needle
to fluctuate rapidly at idle but steady as the engine speed is increased. A
, leaking intake manifold gasket or late ignition timing would cause a steady
low reading. A weak valve spring would cause the gauge needle to fluctuate
as engine speed increased.
◍ A vacuum gauge is connected to the intake manifold of an engine running at
idle. The pointer on the gauge fluctuates rapidly but steadies as the engine
speed is increased. The test results indicate:.
Answer: Worn valve guides - Worn valve guides would cause the gauge
needle to fluctuate rapidly at idle but steady as the engine speed is increased.
A leaking intake manifold gasket or late ignition timing would cause a
steady low reading. A weak valve spring would cause the gauge need to
fluctuate as engine speed increased.
◍ A technician takes a compression reading on a 4-cylinder engine, and gets
readings of 140, 135, 135, and 40 psi. Then he preforms a wet compression
test, and the readings are almost the same as those in the first test.
Technician A says that a burned valve could cause these readings.
Technician B says that a broken piston ring could cause these readings. Who
is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B.
Answer: The correct answer is A, only technician A is correct. A burned
valve will not allow the cylinder to build compression, and the results from
wet and dry compression tests will be the same. If piston rings (or worn
cylinder walls) were at fault, compression readings from a wet test would
exceed dry test results.
◍ Technician A says that retarded valve timing can cause high cylinder
compression readings. Technician B says that a lean air/fuel mixture can
cause a high intake manifold vacuum reading. Who is right?
A. Technician A only
B. Technician B only
, C. Both A and B
D. Neither A or B.
Answer: The correct answer is D, neither technician is right. Technician A is
wrong because retarded valve timing will cause the valves to open and close
at the wrong time, thereby reducing compression and manifold vacuum
readings. Retarded valve timing can be caused by a loose timing belt or
chain jumping one or more teeth. Technician B is wrong because a low but
steady manifold vacuum reading may be caused by a lean air/fuel mixture.
Air leaks or vacuum leaks can cause a lean condition and are common
causes of rough idle, hesitation, stalling and hard starting. If the mixture is
artificially enriched by injecting propane into the induction system, and
engine running lean should speed up and the vacuum reading should rise.
◍ A technician takes a compression reading on a 4 cylinder engine, a gets
reading of 140, 135, 135 and 40 psi. The he preforms a wet compression
test, and the readings are almost the same as those in the first test.
Technician A says that a burned valve could cause these readings.
Technician B says that a broken piston ring could cause these readings. Who
is right?.
Answer: Technician A - Only technician A is correct. A burned valve will
not allow the cylinder to build compression, and the results from wet and
dry compression test will be the same. If piston rings (or worn cylinder
walls) were at fault, compression readings from a wet test would exceed dry
test results.
◍ An engine is being rebuilt and the crankshaft connecting rod journals have
been ground undersize. Specifications show that the original connecting rod
journal size was 2.1228-in. 2.1236-in. If the journals now measure
2.1032-in., what size bearings should be used?
A. 0.001-in. undersize
B. 0.010-in. undersize
C. 0.020-in. undersize
D. 0.030-in. undersize.
Answer: The correct answer is C. Adding 0.020 to 2.1032 is 2.1232, which
TEST – CUMULATIVE CERTIFICATION
SCRIPT 2026 QUESTIONS WITH
SOLUTIONS GRADED A+
◍ A compression test shows that one cylinder is too low. A leakage test on that
cylinder shows that there is excessive leakage. During the test, air could be
heard coming from the tailpipe. Which of the following could be the cause?.
Answer: An exhaust valve not seating - If an exhaust valve is not seating, air
will leak from the combustion chamber by way of the valve out to the
tailpipe and make an audible sound. Broken rings or a bad head gasket
would have air leaking through the oil filler or cooling system.
◍ A compression test shows that one cylinder is too low. A leakage test on that
cylinder shows that there is excessive leakage. During the test, air could be
heard coming from the tailpipe. Which of the following could be the cause?
A. Broken piston rings
B. Bad head gasket
C. Bad exhaust gasket
D. An exhaust valve not seating.
Answer: The correct answer is D. If an exhaust valve is not seating, air will
leak from the combustion chamber by way of the valve out to the tailpipe
and make an audible sound. Broken rings or a bad head gasket would have
air leaking through the oil filler or cooling system.
◍ Technician A says that main bearing oil clearance can be checked with
Plastigauge. Technician B says that main bearing oil clearance can be
checked with dial bore gauge. Who is right?.
Answer: Both A and B - Either method can be used to check main bearing
, oil clearance.
◍ Technician A says that main bearing oil clearance can be checked with
plastigage. Technician B says that main bearing oil clearance can be
checked with a dial bore gauge. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B.
Answer: The correct answer is C, both technicians are right. Either method
can be used to check main bearing oil clearance.
◍ Which of the following is NOT a method of correcting excessive valve
stem-to-guide clearance?
A. Knurling the valve stem
B. Knurling the guide
C. Reaming for oversize
D. Guide replacement.
Answer: The correct answer is A. The valve stem is hardened and cannot be
knurled.
◍ Which is NOT a method of correcting excessive valve stem-to-guide
clearance?.
Answer: Knurling the valve stem - The valve stem is hardened and cannot
be knurled.
◍ A vacuum gauge is connected to the intake manifold of an engine running at
idle. The pointer on the gauge fluctuates rapidly but steadies as the engine
speed is increased. The test results indicate:
A. A leaking intake manifold gasket
B. Worn valve guides
C. Late ignition timing
D. A weak valve spring.
Answer: The correct answer is B. Worn valve guide could cause the needle
to fluctuate rapidly at idle but steady as the engine speed is increased. A
, leaking intake manifold gasket or late ignition timing would cause a steady
low reading. A weak valve spring would cause the gauge needle to fluctuate
as engine speed increased.
◍ A vacuum gauge is connected to the intake manifold of an engine running at
idle. The pointer on the gauge fluctuates rapidly but steadies as the engine
speed is increased. The test results indicate:.
Answer: Worn valve guides - Worn valve guides would cause the gauge
needle to fluctuate rapidly at idle but steady as the engine speed is increased.
A leaking intake manifold gasket or late ignition timing would cause a
steady low reading. A weak valve spring would cause the gauge need to
fluctuate as engine speed increased.
◍ A technician takes a compression reading on a 4-cylinder engine, and gets
readings of 140, 135, 135, and 40 psi. Then he preforms a wet compression
test, and the readings are almost the same as those in the first test.
Technician A says that a burned valve could cause these readings.
Technician B says that a broken piston ring could cause these readings. Who
is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B.
Answer: The correct answer is A, only technician A is correct. A burned
valve will not allow the cylinder to build compression, and the results from
wet and dry compression tests will be the same. If piston rings (or worn
cylinder walls) were at fault, compression readings from a wet test would
exceed dry test results.
◍ Technician A says that retarded valve timing can cause high cylinder
compression readings. Technician B says that a lean air/fuel mixture can
cause a high intake manifold vacuum reading. Who is right?
A. Technician A only
B. Technician B only
, C. Both A and B
D. Neither A or B.
Answer: The correct answer is D, neither technician is right. Technician A is
wrong because retarded valve timing will cause the valves to open and close
at the wrong time, thereby reducing compression and manifold vacuum
readings. Retarded valve timing can be caused by a loose timing belt or
chain jumping one or more teeth. Technician B is wrong because a low but
steady manifold vacuum reading may be caused by a lean air/fuel mixture.
Air leaks or vacuum leaks can cause a lean condition and are common
causes of rough idle, hesitation, stalling and hard starting. If the mixture is
artificially enriched by injecting propane into the induction system, and
engine running lean should speed up and the vacuum reading should rise.
◍ A technician takes a compression reading on a 4 cylinder engine, a gets
reading of 140, 135, 135 and 40 psi. The he preforms a wet compression
test, and the readings are almost the same as those in the first test.
Technician A says that a burned valve could cause these readings.
Technician B says that a broken piston ring could cause these readings. Who
is right?.
Answer: Technician A - Only technician A is correct. A burned valve will
not allow the cylinder to build compression, and the results from wet and
dry compression test will be the same. If piston rings (or worn cylinder
walls) were at fault, compression readings from a wet test would exceed dry
test results.
◍ An engine is being rebuilt and the crankshaft connecting rod journals have
been ground undersize. Specifications show that the original connecting rod
journal size was 2.1228-in. 2.1236-in. If the journals now measure
2.1032-in., what size bearings should be used?
A. 0.001-in. undersize
B. 0.010-in. undersize
C. 0.020-in. undersize
D. 0.030-in. undersize.
Answer: The correct answer is C. Adding 0.020 to 2.1032 is 2.1232, which
