If the engine overheats during long periods of idling but runs normally at highway speeds, the problem is most likely _____.
A) defective thermostat
B) defective water pump
C) defective cooling fan
D) defective radiator

Question

Quizplus · Accepted Answer

The cooling fan is responsible for maintaining airflow through the radiator when the vehicle is not moving. If it is defective, the engine may overheat during idling but run normally at highway speeds when natural airflow cools the engine.

If the Engine Overheats During Long Periods of Idling but Runs