Engine Test Exam Questions With Complete Solutions
A running compression test indicates a possible restriction on
the intake side of a cylinder. What should the technician do
next? Correct Answer Inspect the suspect components.
A running compression test is performed on each cylinder in two
parts. Technician A says after removing the spark plug and
grounding the plug wire, the first part is to install the gauge, start
the engine and snap the throttle open and record the reading on
each cylinder.
Technician B says after removing the plug and grounding the
wire, the first part is to install the gauge, start the engine and
press and release the bleed valve and record the stabilized
reading in each cylinder. Who is correct? Correct Answer
Technician B
A vehicle has black smoke coming from the exhaust after the
engine is warmed up. Technician A says this may indicate worn
valve springs. Technician B says this may indicate an
excessively rich fuel mixture. Who is correct? Correct Answer
Technician B
An engine has one cylinder that measured substantially lower
than specifications on a compression test. Technician A says a
cylinder leakage test should be performed only on the cylinder
with low compression pressure. Technician B says a cylinder
leakage test should be performed on all cylinders. Who is
correct? Correct Answer Technician A
, An engine's vacuum is being tested with a gauge. When the
throttle is snapped wide open momentarily, the gauge drops to
zero and then reaches a high of 20 inches. Technician A says
this could indicate worn piston rings. Technician B says the
reading should have reached about 27 inches. Who is correct?
Correct Answer Both Technician A and Technician B
An engine's vacuum is being tested with a gauge. When the
throttle is snapped wide open momentarily, the gauge drops to
zero and then reaches a high of 20 inches. Technician A says
this could indicate worn piston rings. Technician B says the
reading should have reached about 27 inches. Who is correct?
Correct Answer Both Technician A and Technician B
During a running compression test, a cylinder rises to about 80%
of the cranking compression pressure when the throttle is
snapped to wide open. Technician A says this may indicate a
worn camshaft lobe. Technician B says this may indicate
excessive carbon buildup. Who is correct? Correct Answer
Technician A
Engine mechanical testing should be performed in all of the
following situations, EXCEPT: Correct Answer before
performing major engine repair.
On an engine with a separate fuel injector for each cylinder,
cylinder power balance tests may involve: Correct Answer
disconnecting the fuel injector wire connection at each
individual injector one at a time.
A running compression test indicates a possible restriction on
the intake side of a cylinder. What should the technician do
next? Correct Answer Inspect the suspect components.
A running compression test is performed on each cylinder in two
parts. Technician A says after removing the spark plug and
grounding the plug wire, the first part is to install the gauge, start
the engine and snap the throttle open and record the reading on
each cylinder.
Technician B says after removing the plug and grounding the
wire, the first part is to install the gauge, start the engine and
press and release the bleed valve and record the stabilized
reading in each cylinder. Who is correct? Correct Answer
Technician B
A vehicle has black smoke coming from the exhaust after the
engine is warmed up. Technician A says this may indicate worn
valve springs. Technician B says this may indicate an
excessively rich fuel mixture. Who is correct? Correct Answer
Technician B
An engine has one cylinder that measured substantially lower
than specifications on a compression test. Technician A says a
cylinder leakage test should be performed only on the cylinder
with low compression pressure. Technician B says a cylinder
leakage test should be performed on all cylinders. Who is
correct? Correct Answer Technician A
, An engine's vacuum is being tested with a gauge. When the
throttle is snapped wide open momentarily, the gauge drops to
zero and then reaches a high of 20 inches. Technician A says
this could indicate worn piston rings. Technician B says the
reading should have reached about 27 inches. Who is correct?
Correct Answer Both Technician A and Technician B
An engine's vacuum is being tested with a gauge. When the
throttle is snapped wide open momentarily, the gauge drops to
zero and then reaches a high of 20 inches. Technician A says
this could indicate worn piston rings. Technician B says the
reading should have reached about 27 inches. Who is correct?
Correct Answer Both Technician A and Technician B
During a running compression test, a cylinder rises to about 80%
of the cranking compression pressure when the throttle is
snapped to wide open. Technician A says this may indicate a
worn camshaft lobe. Technician B says this may indicate
excessive carbon buildup. Who is correct? Correct Answer
Technician A
Engine mechanical testing should be performed in all of the
following situations, EXCEPT: Correct Answer before
performing major engine repair.
On an engine with a separate fuel injector for each cylinder,
cylinder power balance tests may involve: Correct Answer
disconnecting the fuel injector wire connection at each
individual injector one at a time.
