What is the purpose of a cooling fan?

• A. To improve fuel economy
• B. To prevent engine overheating
• C. To reduce emissions
• D. To cool the exhaust system

Answer: (B)

The main idea is that the cooling fan's job is to prevent the engine from overheating by moving air through the radiator to cool the engine coolant. The engine heats the coolant as it runs, and the radiator transfers that heat to the air. When the car is moving slowly or idling, there isn’t enough natural airflow, so the fan turns on to pull or push air across the radiator. Keeping the coolant temperature in the safe range protects the engine from damage like warped metal or a blown head gasket and helps maintain reliable performance.

It isn’t there to directly improve fuel economy or reduce emissions, and it doesn’t cool the exhaust system—the exhaust is handled separately and isn’t cooled by the radiator or the cooling fan.