Deck 26: Engine Condition Diagnosis

Question 1

Technician A says that the paper test could detect a burned valve. Technician B says that a grayish white stain on the engine could be a coolant leak. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Answer 1

Both technicians A and B

Question 2

Two technicians are discussing oil leaks. Technician A says that an oil leak can be found using a fluorescent dye in the oil with a black light to check for leaks. Technician B says a white spray powder can be used to locate oil leaks. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Answer 2

Both technicians A and B

Question 3

The vacuum reading shown was taken from an engine at idle speed. The reading indicates that ________.

A)The timing is retarded
B)The engine is in good mechanical condition
C)The idle speed is too low
D)A valve is out of adjustment

Answer 3

The engine is in good mechanical condition

Question 4

Normal exhaust back pressure should be 2.5 PSI of more.

Question 5

A technician is performing a cylinder leak test. The leakage on all cylinders is less than 10% on all cylinders except for one, which indicates 80% leakage. What should the technician do?

A)Grind the valves
B)Replace the piston rings on the 40% cylinder
C)Replace the head gasket
D)Repeat the test (cylinder was not at TDC)

Question 6

As with cranking compression, the running compression pressure at idle of all cylinders should be equal and ________ the cranking compression readings.

A)The same as or higher
B)The same as
C)Higher than
D)Lower than

Question 7

During a dry compression test the first puff of the test shows 50 PSI and the maximum reading after 4 strokes is 150 PSI. This indicates ________.

A)Weak piston rings
B)A hole in the piston
C)A good cylinder
D)A bad spark plug

Question 8

Engine cranking vacuum should be ________.

A)2.5 in. Hg or higher
B)Over 25 in. Hg
C)6 to 16 in. Hg
D)17 to 21 in. Hg

Question 9

A vehicle's oil pressure warning light is on. Technician A says that the pressure sending unit should be replaced and the vehicle re-checked. Technician B says that a mechanical oil pressure gauge should be used to check the oil pressure before replacing the sending unit. Which technician is correct?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 10

Most mechanical engine problems are caused by which of these?

A)Overheating
B)Fuel Loss
C)High RPM
D)Overcooling

Question 11

Technician A says that the first step in diagnosing engine condition is to perform a thorough visual inspection. Technician B says that oil leaks can be found by measuring straight up from where the oil drips on the floor. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 12

All of these are procedures that can help a service technician to diagnose engine faults, EXCEPT ________.

A)Compression test
B)Cylinder leakage test
C)Fuel level test
D)Vacuum test

Question 13

Technician A says that a compression test can be used to test the condition of connecting rods. Technician B says that a cylinder leakage test fills the cylinder with compressed air, and the gauge indicates the percentage of leakage. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 14

Which of these smoke types indicates excessive fuel being burned in the combustion chamber?

A)White
B)Blue
C)Grey
D)Black

Question 15

Which of these smoke types indicates oil being burned in the combustion chamber?

A)Grey
B)White
C)Black
D)Blue