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How Does a Radiator Keep an Engine Cool?


You’re driving along when you notice steam coming out from under your hood. You stop immediately to check the problem. Pop open the hood and it reveals that your car radiator has lost its coolant because a hose busted. You have to call for help because it will damage the engine if you try to drive the vehicle. You may know this fact but not understand exactly how the radiator does its job to keep the engine cool.

One hot engine

The engine runs at a high temperature during combustion. The friction of the pistons moving up and down inside of the cylinders create friction. If the engine gets too hot, it can cause the pistons to meld to the cylinder or “seize up” and stop working. You don’t want this to happen because it means replacing or rebuilding the engine.

To keep the engine cool, channels run throughout the engine block and cylinder head. All of the channels join to one outlet. Coolant, which is a mix of antifreeze and water, runs through these channels from the radiator. When the coolant becomes hot, a pump moves it from the engine to the radiator. Air passing through the radiator carries away the excess heat of the coolant. Then, the coolant is ready to go back to work cooling the engine.

The radiator must continue to work properly or it can’t cool off the engine. That’s why you should never run your vehicle if the radiator has sprung a leak or isn’t working correctly. An overheated engine will cause you even more problems and be costly to repair. If your radiator does need to be replaced, contact a reliable mechanic as soon as possible.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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