What is Engine Cooling?

Mary McMahon
Mary McMahon

Engine cooling is a process that helps an engine maintain a steady temperature and avoid overheating. This ensures that the engine operates at maximum efficiency and prevents damage to the engine and its components. There are a number of methods that can be used to cool engines large and small, and the cooling system is an integral part of the components that make the engine function.

Woman holding a book
Woman holding a book

Engines use chemical reactions to generate heat and mechanical energy. The internal combustion engine is a commonly used example of an engine; it works by using controlled explosions to push pistons that make the engine move, converting it into mechanical energy that can be used to put a vehicle in motion. This process is far from efficient, however. A great deal of heat is created during the process, and it can quickly rise to dangerous levels.

When engines are designed, their developers design them to run at an optimal temperature. An engine cooling system allows an engine to heat up fast to reach this optimal point, and then forces the engine to hold that temperature. Engines that run too cold or too hot will wear out quickly. Catastrophic failure of some engine components can even result in permanent damage to the entire engine.

Air cooling systems for engines were once very popular. Such systems draw air over or through the engine to move the waste heat out and vent it away. Today, liquid cooling is more common. With liquid cooling, water and other fluids are circulated to absorb the heat of the engine and keep the temperature down. The fluid mix varies depending on the operating temperature of the engine and the conditions that can arise while the engine is running.

The engine cooling system includes fans to move hot air, along with hoses for air and fluids used to wick away waste heat. People may have noticed that even with cooling, engines run very hot, and it can be dangerous to touch an engine that has just been running. Usually engines are mantled to shield the rest of the engine compartment from the heat.

When an engine cooling system fails, the engine can overheat. Some engines automatically shut off when they get too hot or signal the operator as a warning. The engine must be allowed to fully cool before it can be run again, and if it continues to overheat, it may require servicing to find out why the engine cooling system is not working correctly.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@Laotionne - There are many reasons a car might overheat, and some of them are pretty simple repairs.

I borrowed my uncle's convertible Corvette when I was in high school. I used the car to drive my girlfriend in the local parade. She was some kind of queen. I don't remember which one.

Everything was going perfectly. I was driving a cool car, which I had cleaned and shined. I was dating a parade queen who was very hot. I was on top of the world. Then halfway through the parade the car started to overheat.

Do you have any idea how embarrassing it is to be driving down the middle of the street and have everyone along the route shouting at you that there is steam coming from the hood of your car?

We didn't finish the parade. My uncle looked at the car and the problem was that there was a small hole in a water hose and engine coolant or some type of liquid was leaking out onto the hot engine. My uncle wrapped duct tape around the hose and drove the car home with no problems.


@Laotionne - If your car is getting too hot and you are getting a warning light, or if the fluid is boiling out of the engine then you have a problem. Cars equipped with engine cooling systems that are designed in a way that the engine should not overheat at all. Like this article says, the engine is going to get hot, but when it overheats your engine is in danger.

Even if the heating problem is happening only occasionally, you should be concerned. Every time the engine gets too hot there is a risk of permanent damage to the engine. Replacing a motor because something cracked when it got too hot is no fun, and this is will be very expensive.

You should have someone take a look at your car and figure out the problem, so it can be repaired before you end up with a costly repair bill.


My car overheats sometimes, but not most of the time. Usually it runs fine and with no heating problems. The overheating happens mostly during really hot weather. Is this normal or should the engine cooling liquid in my engine keep the engine from getting too hot no matter how hot the temperature is outside?

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