Deck 3: Diagnosing Engine Problems

Question 1

An infrared analyzer can be used to check the radiator for combustion leaks.

Answer 1

False

Question 2

A rich air-fuel mixture could cause a catalytic converter to overheat and melt.

Answer 2

False

Question 3

Highway driving can result in extra fuel and water dilution in the oil.

Answer 3

True

Question 4

Excessive clearance at a connecting rod bearing journal will cause a rod knock.

Question 5

Technician A says grounding out a plug wire to a cylinder with a cracked piston will can increase the noise. Technician B says a rod knock will become quieter as its cylinder is grounded. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 6

List several causes of engine overheating.

Question 7

Oil consumption problems are being discussed. Technician A says a lack of regular services can cause the oil control rings to plug. Technician B says worn compression rings can cause oil consumption problems. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 8

If an engine will not turn over in either direction, it could be due to a broken crankshaft.

Question 9

Engine operation is being discussed. Technician A says preignition can cause engine damage. Technician B says carbon deposits on the pistons can increase the compression ratio. Who is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 10

An engine exhibits a low, steady vacuum reading. This could indicate _____.

A) a stuck valve
B) an improper ignition timing
C) plugged exhaust
D) bad compression rings

Question 11

Technician A says an indication of preignition could be a hole burned in the center of a piston. Technician B says detonation is an explosion inside the cylinder. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 12

Comparing premium fuel to regular fuel, the burn time of premium fuel is _____.

A) significantly shorter
B) only slightly shorter
C) longer
D) nearly the same

Question 13

During a compression test, a cylinder shows lower readings than expected. Technician A squirts a tablespoon of oil into the cylinder and the compression raises. He says this indicates a problem with the rings. Technician B says a running compression test should be about one-quarter of that of a cranking compression test. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 14

Technician A says a faulty head gasket can cause the oil to mix with coolant. Technician B says this is called cross fluid contamination. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 15

Technician A says carbon removal additives can damage the muffler. Technician B says if the rpm rises when shorting a cylinder out, it could indicate a vacuum leak. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 16

When does preignition occur?

Question 17

Technician A says that an air-fuel mixture that is too lean can cause burned internal engine parts. Technician B says an overly rich mixture can cause oil wash from cylinder walls. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 18

Oil leaks are being discussed. Technician A says a blue lamp can be used to locate an oil leak after a dye has been installed in the crankcase. Technician B says it is a black light that is used. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 19

Technician A says that valvetrain noise will occur at half the speed of engine rpm. Technician B says valvetrain noises coming from inside the timing cover can be caused by a bad timing chain or chain guide. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician

Question 20

Technician A says if you remove the PCV valve from the valve cover and plug the end with your finger, the idle will increase if the valve is good. Technician B says that when you block the flow to the PCV valve, it will richen the air-fuel mixture. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician