Cooling system 101


The number one job of the cooling system is to keep the engine from overheating. It does this by moving the heat away from the engine to the surrounding air. Its second job is to help the engine heat up quickly to the ideal temperature for combustion, which is when the coolant is between 180-250 degrees. (The ideal temperature varies for different cars and trucks.)

When your engine is at ideal temperature:

  • The combustion chamber is hot enough to fully vaporize the fuel, for better combustion and lower emissions.
  • The oil used to lubricate the engine thins out and becomes more slippery. The engine parts move more freely, and the engine wastes less power moving its own components around.
  • Metal parts wear less.

This is one reason that frequent short trips are harder on your engine than longer ones. The engine doesn't have time to fully heat up before you shut it off again.

Almost all cars and trucks on the road today use liquid to cool the engine. The cooling system passes fluid through pipes and passageways in the engine. It absorbs heat as it goes, cooling the engine. When it leaves the engine, it goes to the radiator. The heat transfers (radiates) from the fluid to the air at the radiator.

A water pump (really a coolant pump) pushes the coolant through the system.

Some older cars, and very few modern cars, are air-cooled. Instead of circulating fluid through the engine, the engine block is covered in aluminum fins that conduct the heat away from the cylinder. A powerful fan forces air over these fins, which cools the engine by transferring the heat directly to the air.

Keeping the engine cool is a critical job. Without it, the engine melts into a solid block. It's critical to keep the water pump, radiator, hoses and liquid coolant working to protect your engine from excess heat.

Bring your car or truck to any of our stores for a free cooling system inspection.

Coolant System Flush & Fill
What does the water pump do?
Routine Services & Fluids