Deck 23: Engine Mechanical Testing and Service

Question 1

Which of the following may contribute to detonation?

A)A lean air/fuel ratio
B)A rich air/fuel ratio
C)A malfunctioning EGR system
D)Both A and C

Answer 1

D

Question 2

A scan tool is usually required to perform a compression test on a hybrid vehicle.

Answer 2

True

Question 3

If a low-compression cylinder is identified, a ___________ ___________ test can help determine where the pressure is going.

Answer 3

cylinder leakage

Question 4

Technician A says automatic transmission fluid is red and easily identified as a leak.Technician B says very old fluid may not appear red and may look like engine oil or power steering fluid.Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 5

A ___________ tester is used to diagnose a restricted exhaust system.

Question 6

A running compression test is done to check the breathing ability of the engine.

Question 7

What type of noise will be caused by a piston slap?

A)A sharp, metallic rapping noise that occurs with the engine idling.
B)A hollow, bell-like noise that is most often occurring during cold engine warmup
C)A light, rapping noise at speeds above 35 mph.
D)A heavy thumping knock when the engine is first started

Question 8

An engine with a blown head gasket will usually emit black smoke.

Question 9

White exhaust smoke indicates excessive fuel being burned.

Question 10

If an engine is experiencing detonation, there may be a fault in the ___________ ________ circuit.

Question 11

If the timing belt breaks on a (an) ______________ engine, the valves can contact the pistons.

Question 12

Which of these tools is used to perform a relative compression test?

A)pressure gauge
B)scan tool
C)inductive ammeter
D)All of the above

Question 13

Black smoke emitted from a diesel engine indicates:

A)oil entering the combustion chamber.
B)a rich fuel mixture.
C)a lean fuel mixture.
D)coolant entering the combustion chamber.

Question 14

Engine oil pressure testing is being discussed.Technician A says that oil pressure should be tested with the engine cold.Technician B says low oil pressure can mean that major engine repairs are needed.Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 15

Where should the piston be during a valve lash adjustment?

A)TDC compression stroke
B)TDC exhaust stroke
C)BDC compression stroke
D)BDC exhaust stroke

Question 16

Blue exhaust smoke means that engine oil is being burned in the combustion chamber.

Question 17

__________ __________ can display voltage and amperage over time, making them very useful for testing sensors and other components.

Question 18

During a cylinder leakage test, air is heard coming from the throttle body.Which of these is the most likely cause?

A)A burned exhaust valve
B)A burned intake valve
C)A blown head gasket
D)A cracked block

Question 19

The ________ is used to determine if each cylinder is contributing power to the overall engine output.

A)four gas analysis
B)snap throttle test
C)vacuum test
D)power balance test

Question 20

During a compression test, the pressure should not vary more than _________ percent between cylinders.

A)10
B)12
C)15
D)20