Car Running Hot But Not Overheating? (9 Reasons Why)

Since most cars run on gas and an internal combustion process, you can expect your car to emit some heat each time you use it. However, it can be alarming once your car starts to feel very warm.

You may be wondering why your car is running hot but not overheating. I did some digging, and here is what I learned!

Car Running Hot But Not Overheating?

A car running hot but not overheating occurs because of an issue with the cooling system. Usually, it is because there is not enough coolant circulating the engine. Moreover, other issues can keep the coolant from going around your car’s engine, such as a bad sensor, thermostat, radiator fans, etc.

Are you interested in learning about more reasons why your car runs hot without overheating? I compiled a list of possible reasons below, so read on!

1. Faulty Sensor

One of the most common reasons that your car is running hot yet not overheating is that you have a bad sensor.

There are many sensors in your car, and your car can run hot yet not overheat because you have a bad coolant temperature sensor.

Generally, a coolant temperature sensor is meant to check the temperature of your coolant to send information to the engine control unit.

When the coolant temperature sensor goes bad, it can stop the engine control unit from finding ways to keep the engine from overheating.

If there is a minor mistake in the coolant temperature sensor reading, your car may not be able to cool down and cause your car to run hot.

Read More:  Why Is My Cruise Control Not Working? (9 Reasons Why)

2. Bad Water Pump

Another common reason why your car is hot but not overheating is that you have a bad water pump.

As you can guess from the name, the water pump is in charge of moving water back and forth from the radiator and motor.

If the water pump goes bad, there will be little to no movement of water, which can lead to your car getting very hot.

Moreover, you can tell taht you have a faulty water pump when you notice that your car has a reduction in efficiency.

3. Coolant

Generally, most people’s cars get very hot because they have little to no coolant in their cars.

Coolant is a liquid that keeps the car’s engine from overheating by lubricating the moving engine parts and removing excess heat.

If you do not have enough coolant in your car, the coolant will not be able to efficiently cool down your engine.

Usually, having very little or no coolant will make your engine overheat, so you may only need to top off your coolant if you just notice that your car is running hot but not overheating.

4. Damaged Head Gasket

While a damaged head gasket usually leads to an overheating car, it can make your car run hot if you just started the car or if there is a small amount of damage.

When a head gasket goes bad, the coolant and water mixture will leak and reach the car’s radiator.

If this happens, you will likely have steam coming out of the radiator and have a very hot car.

Read More:  Why Are Car Loans Always Secured With Collateral? (9 Reasons Why)

5. Bad Thermostat

Bad Thermostat

Another crucial part of your car’s cooling system is the thermostat since the thermostat will regulate how and when coolant flows through the engine.

Generally, the coolant thermostat is meant to open and close a valve to release coolant according to the car’s temperature.

When your thermostat is defective, coolant will circulate through the engine too fast, causing your engine to get hot.

When the coolant flows too quickly, there will not be enough time for the coolant to efficiently cool down your car.

6. Faulty Radiator Cap

Typically, there is a radiator cooling cap that regulates the pressure of the coolant, and coolant can overflow if the radiator cap is faulty.

Usually, this occurs because there is too much pressure, which can lead to boiling and in rare cases, an explosion. 

7. Bad Temperature Gauge

Similar to the thermostat, your car has a temperature gauge that helps read the temperature of the engine to know when the engine should be cooled down.

However, the temperature gauge can go bad and give the wrong temperature reading, which means that there will be no coolant circulating and you will not know if your engine is overheating.

Typically, you can check to see if your temperature gauge is working properly by touching a radiator hose to find out if the radiator hose is hot.

8. Cooling Fan

Usually, there are fans in your radiator that helps keep your engine from overheating by cooling down the coolant.

However, the cooling fan can get defective due to a clogged or stuck blade, a broken blade, etc.

Read More:  Why Is My Car Jerking When I Give It Gas? (11 Reasons Why)

When this happens, there will be reduced airflow and resistance across your radiator, and that will prevent efficient cooling because the coolant will lack circulation. 

9. Damaged Or Clogged Radiator

Generally, your car has a radiator tha helps get rid of extra heat that comes from your engine to prevent overheating.

However, the radiator can get damaged or clogged over time, which will make it difficult or impossible for the radiator to cool the car down.

Typically, you may have a slightly damaged or clogged radiator is your car runs hot without overheating since a completely clogged or damaged radiator will make the car overheat.

Usually, it is best to address the problem with your radiator immediately before it gets worse and car starts to overheat.


Usually, a car runs hot without overheating because there is a problem with the coolant, such as lacking coolant or a coolant leak.

Moreover, other parts of your cooling system, such as the thermostat or radiator, can fail, which can make your car run hot.

Leave a Comment