ASE Engine Repair A1 3

Question 1

During an engine rebuild, a technician measures the piston ring end gap and finds it is smaller than the manufacturer's minimum specification. What is the correct action?

Accepted Answer

File the ring ends to increase the gap to spec

Answer

Piston ring end gap must be within specification. If the gap is too small, heat expansion during operation can cause the ring ends to butt together, collapsing the ring and damaging the cylinder wall. The correct fix is to file the ring ends carefully until the gap meets the minimum specification.

Question 2

A technician is checking main bearing clearance using Plastigage. After removing the cap, the Plastigage strip is wider than the comparison scale indicates. What does this mean?

Accepted Answer

The bearing clearance is greater than specification

Answer

Plastigage works by being compressed between the journal and bearing. After assembly and disassembly, its width is compared to the scale. A wider crushed strip means less compression occurred, which indicates the bearing clearance is greater (looser) than specification. Excess clearance leads to low oil pressure and bearing noise.

Question 3

What is the purpose of a valley gasket (valley pan gasket) in a V-type engine?

Accepted Answer

It seals the lifter valley area to prevent oil leaks into the intake system

Answer

In many V-type engines, the valley between the cylinder banks can be exposed to oil splashing from the lifters and camshaft. The valley pan gasket seals this area to prevent oil from leaking into the intake manifold or combustion chambers, which would cause blue smoke and oil consumption.

Question 4

A technician notices a deep groove worn into a camshaft lobe on one cylinder. Which component is most likely the primary cause of this failure?

Accepted Answer

Failed hydraulic lifter not rotating on the lobe

Answer

Hydraulic lifters (and solid lifters) are designed to rotate slightly as they follow the cam lobe. This rotation distributes wear evenly. If a lifter seizes and stops rotating, it will wear a groove into the lobe in the same spot on every revolution. Lobe failure is almost always associated with a stuck or collapsed lifter.

Question 5

Which method is used to check for a warped cylinder head on a removed head?

Accepted Answer

Place a straightedge and feeler gauge across multiple directions on the deck surface

Answer

A straightedge and feeler gauge is the standard method to check cylinder head flatness. The straightedge is placed lengthwise, crosswise, and diagonally across the head deck surface. A feeler gauge is used to measure any gap between the straightedge and the deck. Warpage beyond the manufacturer's limit requires resurfacing.

ASE Practice Test

ASE Practice Test

ASE Engine Repair A1 3