Automotive Technology Practice Exam 168 Questions Complete

AUTOMOTIVE

TECHNOLOGY PRACTICE

EXAM 168 QUESTIONS

COMPLETE

Question 1: An engine has low oil pressure at hot idle but normal pressure when cold.The oil level and speci�ed viscosity are correct. Which condition is most likely?

Choices:

1) A stuck-open thermostat 2) A restricted air �lter 3) Excessive main or rod bearing clearance 4) Excessive spark plug gap

Correct Answer: Excessive main or rod bearing clearance

Explanation: Excessive bearing clearance allows more oil to escape from the pressurized galleries as the oil warms and thins. That can produce low hot-idle oil pressure even when oil level and viscosity are correct.Page 1

Question 2: During a cylinder leakage test air is heard clearly at the throttle body.Which component is most likely leaking?

Choices:

1) Exhaust valve 2) Piston rings 3) Intake valve 4) Head gasket into coolant passage

Correct Answer: Intake valve

Explanation: Air heard at the throttle body or intake indicates leakage past an intake valve.Ring leakage is usually heard at the crankcase and an exhaust-valve leak at the tailpipe.Question 3: A cooling system repeatedly pushes coolant into the over�ow bottle and shows combustion gases in the coolant. What should the technician suspect �rst?

Choices:

1) Restricted cabin air �lter 2) Weak battery 3) Leaking cylinder-head gasket 4) Worn wheel bearing

Correct Answer: Leaking cylinder-head gasket

Explanation: Combustion gases detected in the cooling system strongly indicate a leak between a combustion chamber and a coolant passage, commonly from a failed head gasket or related sealing surface.Page 2

Question 4: A technician measures crankshaft journal diameter before selecting

replacement bearings. Which tool is most appropriate?

Choices:

1) Feeler gauge 2) Outside micrometer 3) Dial test light 4) Vacuum gauge

Correct Answer: Outside micrometer

Explanation: An outside micrometer accurately measures crankshaft journal outside diameter.Bearing selection depends on precise journal and housing measurements and manufacturer speci�cations.

Question 5: After an engine is rebuilt the oil-pressure warning lamp remains on

during the �rst cranking attempt. What is the best immediate action?

Choices:

1) Stop and verify oil-system priming and pressure 2) Increase engine speed to 3000 rpm 3) Continue cranking until the lamp goes out no matter how long it takes 4) Add coolant to the reservoir

Correct Answer: Stop and verify oil-system priming and pressure

Explanation: A rebuilt engine must establish lubrication quickly. If pressure is not indicated promptly, stop and verify priming, oil supply, �lter installation, pickup sealing, and actual pressure before running the engine.Page 3