Why Is My Car Overheating With a New Thermostat?

There are a few reasons your car could be overheating with a new thermostat, but the most likely culprit is a faulty thermostat. A thermostat is a device that controls how much coolant flows into your engine.

When the coolant reaches its predetermined temperature, the thermostat opens and allows coolant to flow through the engine, cooling it down. If you just replaced your thermostat and still have issues with overheating, check for leaks in your radiator or hoses.

If you notice any leaks, replace those parts immediately to prevent further damage to your car’s engine.

Type of thermostat


These are simple and easy to replace, but they can fail over time and need to be replaced regularly.


These are more complex than mechanical ones, but they’re also more reliable. They can last for years without needing to be replaced, but they do need batteries to work properly.


These may be used in some systems where there is no other option because they don’t require coolant or electricity. However, they tend to wear out quickly and are not as effective at regulating temperatures as other types of thermostats.


Like electric thermostats, electronic ones work by regulating the flow of coolant through a valve that opens and closes based on temperature readings taken internally within each unit’s housing chamber however, unlike electric versions which require batteries, these types instead use small amounts of power from your vehicle’s electrical system whenever needed so as not consume any extra resources.

Why did the thermostat fail?

When your car’s thermostat fails, it can cause the engine to overheat. This is because the thermostat regulates the temperature of the coolant fluid by keeping it in a liquid state. If the engine begins to overheat, however, the thermostat will fail and allow too much coolant fluid to escape into your radiator.

When this happens, you’ll need to replace your thermostat so that no more coolant can escape from your radiator and cause your engine to overheat.

How does the thermostat work?

The thermostat has two parts: an internal spring, which regulates how much pressure can build up inside; and an external spring, which controls when air flows into the engine block.

When it’s cold outside, both springs are closed so that all of the coolants remain in the radiator where they can be heated up by passing through tubes filled with hot water circulating from an engine-driven pump.

When it gets warmer outside, both springs open so that coolant passes through them into an engine block where it can be heated up further before returning to circulate back out through tubes filled with hot water again and then back into.

What causes overheating in my car?

Your thermostat is malfunctioning and not opening or closing properly. This means that the engine cannot efficiently regulate its temperature, and it overheats. Your radiator is clogged with dirt or debris, preventing it from cooling properly.

This can also cause your car’s coolant system to overheat. You have too much air pressure in your tires, which prevents them from dissipating heat properly and leads to overheating.

The water pump in your car has failed, so the cooling system cannot circulate water through the engine block effectively enough to prevent overheating.

What is the purpose of a thermostat?

The thermostat regulates the flow of coolant through your engine by opening and closing, depending on whether or not it is needed. The coolant circulates through the radiator, where it is cooled by air flowing over it, then back into the engine to be reheated when necessary.


The thermostat can be a finicky piece of machinery. If so, we suggest taking it into a mechanic to diagnose the problem.

Steven Hatman
Steven Hatman

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