310S Engine Systems and Repair

Question 1

What is the primary purpose of the crankshaft in an internal combustion engine?

Accepted Answer

To convert reciprocating motion into rotational motion

Answer

To open and close the valves

Answer

To compress the air-fuel mixture

Answer

To circulate coolant through the engine

Question 2

A compression test on a four-cylinder engine shows cylinders 1, 2, and 4 at 150 psi, but cylinder 3 reads 90 psi. What should the technician do next?

Accepted Answer

Perform a wet compression test on cylinder 3

Answer

Replace the head gasket immediately

Answer

Replace the piston rings on cylinder 3

Answer

Condemn the engine block

Question 3

What is the correct method for measuring crankshaft journal wear?

Accepted Answer

Outside micrometer at multiple points on the journal

Answer

Feeler gauge between the journal and bearing

Answer

Dial indicator on the flywheel flange

Answer

Vernier caliper across the journal diameter

Question 4

What does excessive blue smoke from the exhaust at startup indicate?

Accepted Answer

Worn valve stem seals allowing oil to seep into the cylinders

Answer

Coolant leaking into the combustion chamber

Answer

A rich fuel mixture condition

Answer

Catalytic converter failure

Question 5

What is the function of the harmonic balancer on a crankshaft?

Accepted Answer

To dampen torsional vibrations in the crankshaft

Answer

To balance the weight of the flywheel

Answer

To drive the timing chain or belt

Answer

To seal the front of the crankcase

Question 6

During a cylinder leakage test, air is heard escaping from the tailpipe. What component is most likely at fault?

Accepted Answer

Exhaust valve

Answer

Intake valve

Answer

Head gasket

Answer

Piston rings