ASE A1 (Engine Repair) Practice Test 2023 with all the
correct answers- Cumulative
1. an engine miss is being diagnosed using a cylinder leakage test. Technician A says
that any cylinder with over 20% leakage has excessive leakage. Tech B says that air
leaking from the tailpipe indicates a cracked cylinder.
A only
B only
Both A & B
Neither A nor B
A only
If cylinder leakage exceeds 20%, check for air escaping the tailpipe, the PCV valve
opening in the rocker arm cover, and the top of the throttle body or carburetor.
Air leaking from the tailpipe usually indicates an exhaust valve leak
23. during a compression test, a cylinder has 40% of the specified compression reading.
When the tech performs a wet test, the compression reading on this cylinder has 75% of
the specified reading. The cause of the low compression reading could be
worn piston rings
a burned exhaust valve
a bent intake valve
a worn camshaft lobe
worn piston rings
if compression increases during a wet test, this indicates worn piston rings.
Compression would not increase if an exhaust valve is burned, intake valve is bent, or
camshaft lobe is worn.
35. the customer complains that the engine cranks but does not start; the first thing to
check should be
valve train operation
battery voltage
compression
engine vacuum
valve train operation
if the engine cranks properly, the battery is not the problem. Compression would not be
the FIRST test, and because engine vacuum is low during a crank, a vacuum test would
not be conclusive.
40. during a cylinder balance test on an engine with fuel injection, one cylinder provides
very little rpm drop. Tech A says the ignition system may be misfiring on that cylinder.
Tech B says the engine may have an intake manifold vacuum leak.
,A only
B only
Both A & B
Neither A nor B
Both A&B
Both a misfiring ignition system and an intake manifold leak could cause a cylinder to
contribute too little power
54. while discussing basic diagnostic procedures, Tech A says the most complicated
diagnostic tests should be performed first. Tech B says that you should first question the
customer to obtain as much info as possible about the problem
A
B
A&B
Neither
B
Always attempt the more simple diagnosis first
57. with the engine idling, a vacuum gauge connected to the intake manifold fluctuates
(from 15 to 20). These fluctuations may be caused by
late ignition timing
intake manifold vacuum leaks
a restricted exhaust system
sticky valve stems and guides
sticky valve stems and guides
-late ignition timing would result in a low, steady reading
-intake manifold leaks would cause a very low, steady reading
-a restricted exhaust system would cause vacuum to slowly decrease after the engine
was accelerated and held steady
59. oil is leaking from the crankshaft rear main bearing seal on an engine. Tech A says
the oil seal could be faulty. Tech B says the PCV system may not be functioning.
A
B
A&B
Neither
A&B
60. A high-pitched squealing noise is heard during hard acceleration. This may be the
cause of:
intake manifold leak
,the choke stuck closed
fuel system leak
small leak in exhaust manifold
small leak in exhaust manifold
-intake manifold leak causes a high-pitched whistle at idle and low speeds
-carb choke stuck closed will not cause a high-pitched whistle
-fuel system leak normally would not cause a noise
61. a heavy thumping noise occurs with the engine idling, but the oil pressure is normal.
this may be caused by:
worn pistons and cylinders
loose flywheel bolts
worm main bearings
loose camshaft bearings
loose flywheel bolts
-worn pistons and cylinders would cause a thumping noise during acceleration
-worn main bearings cause a thump when the engine is started
-loose camshaft bearings would cause a growling noise at all times
A21. after a vehicle is parked overnight and then started in the morning, the engine has
a lifter noise that disappears after running for a short time. this may be caused by:
low oil pressure
low oil level
worn lifter bottom
excessive lifter leak-down
excessive lifter leak-down
low oil pressure would result in a continuous noise
low oil level would result in a continuous noise
worn lifter bottom would result in a continuous noise
A22. when using a compression tester, the readings on the cylinders are all even, but
lower than spec. this could indicate:
blown head gasket
carbon buildup
cracked head
worn rings and cylinders
worn rings and cylinders
-a low reading on two adjacent cylinders may indicate a blown head gasket
-carbon buildup would cause a high reading
-a low reading on two adjacent cylinders may indicate a cracked head
A36. a cylinder balance test is being performed on an engine to determine which
cylinder is causing a miss. Tech A says that when the faulty cylinder is disabled, engine
, rpm will drop more than for the other cylinders. Tech B says disabling the faulty cylinder
will cause the engine to stall
A
B
Both
Neither
Neither
the faulty cylinder will not cause the engine to stall, neither will it cause the engine to
drop in RPM since it is faulty.
A43. an engine is idling at 750 rpm. the pointer on the vacuum gauge is floating
between 11 and 16 in Hg. The most likely cause is
retarded timing
advanced timing
stuch EGR valve
too lean idle mixture
too lean idle mixture
all others would not result in gauge fluctuation
A63. the first step a Tech should take for diagnosis is:
think of possible causes of the problem
question the customer
road test the vehicle
listen to the customer
listen to the customer
A81. the customer says that the engine requires excessive cranking to start. the LEAST
likely cause of this problem would be:
cracked cylinder block
jumped timing belt
faulty fuel pump
stuck-open EGR valve
cracked cylinder block
A84. which of the following is LEAST likely to cause engine noise?
loose pistons
worn cylinders
worn main bearings
loose camshaft bearings
loose cam bearings
-loose pistons may cause a rapping noise while accel
correct answers- Cumulative
1. an engine miss is being diagnosed using a cylinder leakage test. Technician A says
that any cylinder with over 20% leakage has excessive leakage. Tech B says that air
leaking from the tailpipe indicates a cracked cylinder.
A only
B only
Both A & B
Neither A nor B
A only
If cylinder leakage exceeds 20%, check for air escaping the tailpipe, the PCV valve
opening in the rocker arm cover, and the top of the throttle body or carburetor.
Air leaking from the tailpipe usually indicates an exhaust valve leak
23. during a compression test, a cylinder has 40% of the specified compression reading.
When the tech performs a wet test, the compression reading on this cylinder has 75% of
the specified reading. The cause of the low compression reading could be
worn piston rings
a burned exhaust valve
a bent intake valve
a worn camshaft lobe
worn piston rings
if compression increases during a wet test, this indicates worn piston rings.
Compression would not increase if an exhaust valve is burned, intake valve is bent, or
camshaft lobe is worn.
35. the customer complains that the engine cranks but does not start; the first thing to
check should be
valve train operation
battery voltage
compression
engine vacuum
valve train operation
if the engine cranks properly, the battery is not the problem. Compression would not be
the FIRST test, and because engine vacuum is low during a crank, a vacuum test would
not be conclusive.
40. during a cylinder balance test on an engine with fuel injection, one cylinder provides
very little rpm drop. Tech A says the ignition system may be misfiring on that cylinder.
Tech B says the engine may have an intake manifold vacuum leak.
,A only
B only
Both A & B
Neither A nor B
Both A&B
Both a misfiring ignition system and an intake manifold leak could cause a cylinder to
contribute too little power
54. while discussing basic diagnostic procedures, Tech A says the most complicated
diagnostic tests should be performed first. Tech B says that you should first question the
customer to obtain as much info as possible about the problem
A
B
A&B
Neither
B
Always attempt the more simple diagnosis first
57. with the engine idling, a vacuum gauge connected to the intake manifold fluctuates
(from 15 to 20). These fluctuations may be caused by
late ignition timing
intake manifold vacuum leaks
a restricted exhaust system
sticky valve stems and guides
sticky valve stems and guides
-late ignition timing would result in a low, steady reading
-intake manifold leaks would cause a very low, steady reading
-a restricted exhaust system would cause vacuum to slowly decrease after the engine
was accelerated and held steady
59. oil is leaking from the crankshaft rear main bearing seal on an engine. Tech A says
the oil seal could be faulty. Tech B says the PCV system may not be functioning.
A
B
A&B
Neither
A&B
60. A high-pitched squealing noise is heard during hard acceleration. This may be the
cause of:
intake manifold leak
,the choke stuck closed
fuel system leak
small leak in exhaust manifold
small leak in exhaust manifold
-intake manifold leak causes a high-pitched whistle at idle and low speeds
-carb choke stuck closed will not cause a high-pitched whistle
-fuel system leak normally would not cause a noise
61. a heavy thumping noise occurs with the engine idling, but the oil pressure is normal.
this may be caused by:
worn pistons and cylinders
loose flywheel bolts
worm main bearings
loose camshaft bearings
loose flywheel bolts
-worn pistons and cylinders would cause a thumping noise during acceleration
-worn main bearings cause a thump when the engine is started
-loose camshaft bearings would cause a growling noise at all times
A21. after a vehicle is parked overnight and then started in the morning, the engine has
a lifter noise that disappears after running for a short time. this may be caused by:
low oil pressure
low oil level
worn lifter bottom
excessive lifter leak-down
excessive lifter leak-down
low oil pressure would result in a continuous noise
low oil level would result in a continuous noise
worn lifter bottom would result in a continuous noise
A22. when using a compression tester, the readings on the cylinders are all even, but
lower than spec. this could indicate:
blown head gasket
carbon buildup
cracked head
worn rings and cylinders
worn rings and cylinders
-a low reading on two adjacent cylinders may indicate a blown head gasket
-carbon buildup would cause a high reading
-a low reading on two adjacent cylinders may indicate a cracked head
A36. a cylinder balance test is being performed on an engine to determine which
cylinder is causing a miss. Tech A says that when the faulty cylinder is disabled, engine
, rpm will drop more than for the other cylinders. Tech B says disabling the faulty cylinder
will cause the engine to stall
A
B
Both
Neither
Neither
the faulty cylinder will not cause the engine to stall, neither will it cause the engine to
drop in RPM since it is faulty.
A43. an engine is idling at 750 rpm. the pointer on the vacuum gauge is floating
between 11 and 16 in Hg. The most likely cause is
retarded timing
advanced timing
stuch EGR valve
too lean idle mixture
too lean idle mixture
all others would not result in gauge fluctuation
A63. the first step a Tech should take for diagnosis is:
think of possible causes of the problem
question the customer
road test the vehicle
listen to the customer
listen to the customer
A81. the customer says that the engine requires excessive cranking to start. the LEAST
likely cause of this problem would be:
cracked cylinder block
jumped timing belt
faulty fuel pump
stuck-open EGR valve
cracked cylinder block
A84. which of the following is LEAST likely to cause engine noise?
loose pistons
worn cylinders
worn main bearings
loose camshaft bearings
loose cam bearings
-loose pistons may cause a rapping noise while accel
