ENGINE REPAIR ACTUAL TEST PAPER
COMPLETE QUESTIONS AND ANSWERS
FULL SOLUTION
●● 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.
,●● 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 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.
●● 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 is right in the middle of the standard specifications, so 0.020-in.
undersize bearings should be used.
●● Camshaft lift is defined as:
A. the distance the valves are open
B. the height of the lobes on the camshaft
C. the time the valves stay closed
D. the time the valves stay open
Answer: The correct answer is B. The distance the valves are opened is
defined as valve lift. The time the valves stay open is usually referred to
as duration.
●● Technician A says that the burned valve could be the result of too
little valve lash. Technician B says excessive valve lash could cause very
fast camshaft wear. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
COMPLETE QUESTIONS AND ANSWERS
FULL SOLUTION
●● 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.
,●● 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 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.
●● 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 is right in the middle of the standard specifications, so 0.020-in.
undersize bearings should be used.
●● Camshaft lift is defined as:
A. the distance the valves are open
B. the height of the lobes on the camshaft
C. the time the valves stay closed
D. the time the valves stay open
Answer: The correct answer is B. The distance the valves are opened is
defined as valve lift. The time the valves stay open is usually referred to
as duration.
●● Technician A says that the burned valve could be the result of too
little valve lash. Technician B says excessive valve lash could cause very
fast camshaft wear. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B
