ASE Practice Test #3 2

Question 1

A vehicle has intermittent no-start that the customer describes as occurring only when the engine is hot. The engine cranks but does not start when hot. What should the technician suspect?

Accepted Answer

A heat-sensitive component failure such as a crankshaft position sensor, ignition module, or fuel pump that breaks down when hot and recovers when cool

Answer

Weak battery

Answer

Low coolant level

Answer

Worn starter motor brushes

Question 2

What is the purpose of the PCV (Positive Crankcase Ventilation) system in a gasoline engine?

Accepted Answer

To ventilate the crankcase by drawing blow-by gases (past the piston rings) back through the intake manifold for combustion, preventing pressure buildup and reducing hydrocarbon emissions

Answer

To add fresh air directly into the combustion chamber

Answer

To pressurize the crankcase for better oil distribution

Answer

To cool the engine oil by circulating fresh air through the oil pan

Question 3

A vehicle has a spongy brake pedal that improves after pumping multiple times. What is the MOST likely cause?

Accepted Answer

Air in the brake hydraulic system — compressible air causes the spongy feeling; pumping pushes fluid more firmly against the air bubble, temporarily improving pedal feel

Answer

A leaking brake caliper piston seal

Answer

Low brake fluid in the reservoir

Answer

Warped front brake rotors

Question 4

What is "detonation" (engine knock) in a gasoline engine, and what are the primary causes?

Accepted Answer

Abnormal, spontaneous ignition of the end-gas charge ahead of the spark-ignited flame front, creating a pressure spike — caused by low-octane fuel, advanced timing, carbon deposits, or excessive cylinder temperature

Answer

Normal combustion that occurs before TDC

Answer

A loose engine mount causing a knocking noise

Answer

Fuel injector backfire into the intake manifold

Question 5

Which tool is used to measure the inside diameter of a cylinder bore for wear and out-of-round condition?

Accepted Answer

Dial bore gauge (cylinder bore gauge)

Answer

Outside micrometer

Answer

Vernier caliper

Answer

Feeler gauge

Question 6

When should a torque-to-yield (TTY) fastener be replaced rather than reused?

Accepted Answer

After every removal — TTY fasteners are designed to be used once and are permanently deformed beyond their elastic limit during initial tightening; reuse reduces clamping force and risks fastener failure

Answer

Only when visually damaged

Answer

TTY fasteners can be reused up to 3 times

Answer

Only when the threads are visually stripped