what causes a car to overheat

What Causes A Car To Overheat?

As a driver, there are certain things that could happen to your car while you're on the road and sometimes it could be the worst feeling ever because you're in a hurry and you have to pull over. One of these scenarios that I'm sure you're all familiar with is when the engine is too hot.


You will pull over to let the engine cool down, and it's just too unfortunate, isn't it? Well, overheating sometimes happens to most of our cars, but what causes a car to overheat? I will tell you what, so you'll have a future reference for the things to avoid so this won't happen.

What is Overheating?

The heat is the engine's enemy. Its damages to the car could be worsted that you have to do some repairs or replacements. A lot of things can cause the car to overheat, and it will lead you to perform high-cost repairs and long hours of works especially if the damage is enormous.

Generally, the engine functions properly at a certain temperature. That particular temperature, even though it's too hot when we touch it, is cooler than without a cooling system.

Overheating happens when the engine's temperature rises to the point where it can cause mechanical damages. A temperature of over 240F is enough to cause some problems. The signs that your vehicle is overheating are: engine warning lights, the temperature is in the red zone, and steam is coming out from the engine area.

Is There a Cooling System? How does it Function?

Every engine has a cooling system. Every car engines are air-cooled. To be able to understand my explanation on why and how the engine overheats, you have to be familiar with the parts of the engine's cooling system. It has a thermostat, a water pump, a radiator, a heater core, some coolant hoses and the engine.

The water pump contains impeller in it that circulates the coolant. It looks like a windmill or a fan that is turned by a timing belt or serpentine belt.

The coolant flows through the coolant jacket. It absorbs the heat and carries it out of the engine and into the heater core.

The heater core warms up the interior. It's a small radiator inside the vehicle. The valve controls the hot coolant that passes through the heater core for warm the temperature of the air inside.

A radiator is a long tube bent into shorter coils. The air that passes through the coils disperse the heat from the coolant then reduces the coolant's temperature. After it goes through the radiator, the cooled fluid then will be carried back by the hose to the water pump. The cycle repeats.

What Causes a Car to Overheat?

These are some of the causes of overheating. You should be aware of these so in the future overheating could be avoided.

1. Leak in Cooling System

Sometimes it could be misleading, but I will explain it to you. The leak in your cooling system is not the direct cause of overheated engine. However, the direct cause is the air entering the cooling system. If there is a leak, the coolant level drops and the air is circulated and sucked.

The air can quickly rise to the top of the cooling system since it's lighter than coolant, with that, the result is an airlock. The airlock is the term we use if there's a large bubble in the cooling system that can't be pushed through by the coolant flow. What does this mean? The cooling system stops its circulation, and the coolant inside becomes superheated.

2. Blockage

A blockage is also an indirect cause, but the overheating happened when there's a lack of coolant circulation in the engine. If there is a blockage in the cooling system, its coolant couldn't do its circulation and couldn't disperse heat; the result is engine overheating. Some of the warning signs are the following: an object in the cooling system, mineral deposit blocking the radiator and a malfunctioning thermostat.

3. Failed Water Pump

One of the most frequent and regular causes of overheating is water pump failure. The most active component of your cooling system is the water pump, and it's responsible for coolant circulation maintenance. As the days or months pass, the impeller or the bearing inside the water pump breaks or wears, and it will no longer function. If this happens, the engine overheats.

4. The Coolant Isn't Concentrated Enough

This is a big problem during cold weather when the temperature drops below freezing point. The coolant gels up inside the radiator or engine and causes a blockage. Even during this type of weather, the engine can overheat too if the car's antifreeze gels up and can't circulate. This causes internal damage in the components that will require a repair.

5. A Belt or Chain That Needs to be Checked

You have to check both your timing belt and water pump accessory belt.

Your timing belt or chain is that it turns on the camshaft in your engine in time with the crankshaft. It allows the camshaft to close and open the valves in time, so the engine's performance is on its highest level.

The water pump accessory belt drives the water pump among the other components. The water pump is essential to the engine is kept cool and functions properly. You can tell if there's a problem when you lift the hood and there's an annoying squeak every time the engine is running. The belts should be checked or replaced because if not it might cause problems.

6. Ignoring the Low Oil Light

You might not think about this as a cause, but it is. Some of the overheating situation is caused by lack of oil, and this thing happens a lot more than you think. The oil lubricates the mashing, rumbling and smashing parts of the engine that allow combustion, so the engine is powered and turned on.

Without the oil, the parts will cause friction, and it heats the engine to a level where it is already dangerous. The coolant can't stop the destruction if you lack oil.

Overheating is unstoppable, but if you observe your car and how it functions than just drive it, there is a possibility that it could be avoided. It takes the time to do a lot of checking, but at least you won’t get stuck on the road while driving somewhere important right?

I hope you find this information helpful. Enjoy your ride and never let your car overheat out of the blue! Happy driving!

About the Author Vince Martin

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