ASE Engine Repair A1

Question 1

What is the primary function of the camshaft in an internal combustion engine?

Accepted Answer

To control the timing and operation of intake and exhaust valves

Answer

To pressurize and circulate engine oil

Answer

To regulate coolant flow through the engine block

Answer

To convert the reciprocating motion of pistons into rotational force

Question 2

A technician measures excessive crankshaft end play during an engine rebuild. What is the MOST likely cause?

Accepted Answer

Worn or damaged thrust bearings

Answer

Excessive main bearing clearance

Answer

A warped crankshaft flange

Answer

Incorrect rod bearing crush

Question 3

Which condition would MOST likely cause low compression in one cylinder while all others test normal?

Accepted Answer

A burned or bent valve

Answer

Worn piston rings across the engine

Answer

Incorrect ignition timing

Answer

A clogged fuel injector

Question 4

When performing a cylinder leak-down test, air escaping from the oil filler cap indicates leakage past which component?

Accepted Answer

Worn or damaged piston rings

Answer

A leaking intake valve

Answer

A failed head gasket

Answer

A leaking exhaust valve

Question 5

What is the purpose of measuring main and rod bearing clearance with Plastigage during an engine rebuild?

Accepted Answer

To verify the oil film clearance between the bearing and crankshaft journal

Answer

To measure the bearing crush after cap installation

Answer

To check the hardness of the bearing material

Answer

To confirm the crankshaft is within roundness specifications

Question 6

An engine exhibits excessive oil consumption with blue smoke from the exhaust that is WORST on deceleration. What is the MOST likely cause?

Accepted Answer

Worn or damaged valve stem seals

Answer

Worn piston rings and cylinder walls

Answer

A cracked piston crown

Answer

Excessive positive crankcase ventilation (PCV) flow