Why Does My Car Keep Overheating and What Can I Do About It?

Most people want their car to be able to get them from point A to B without having to worry about if their car is going to start the next time they need to go for a drive. Which is why it can be frustrating if your car is overheating constantly. But what should you do if your car is overheating, and how can you prevent your car from overheating in the future?

The root cause of your engine overheating will usually be traced back to one of the following problems: a coolant leak/low coolant levels, damaged radiator, plugged heater core, stuck thermostat, blown head gasket, faulty water pump, broken radiator fan, or a cracked/damaged coolant hose.

But how do you know which problem is plaguing your car and causing it to overheat? What are the most common symptoms of an overheating car? Keep reading to find out.

Common Causes of An Overheating Engine

Low Engine Coolant

Engine coolant is circulated throughout the engine to cool it down. If you don’t have enough engine coolant in your coolant system then it won’t be able to properly cool down the engine to keep the engine temps low.

You should periodically check the engine coolant levels on your car to make sure that they are up to the appropriate levels. Caution: you should never remove your radiator coolant cap when your engine is hot. Doing so can cause hot engine coolant to shoot out of the radiator and spray all over your body resulting in burns all over your body.

Coolant Leak

One reason why you may be low on coolant is that you have a coolant leak. Coolant hoses are typically the culprit if you have a coolant leak but coolant can also leak out of your radiator if there is an issue with the radiator so that’s something to keep in mind.

Coolant can also leak out of your head gasket if your head gasket is blown or has cracks in it. The good news is that coolant hoses and radiators are usually easy to access and are fairly inexpensive to replace. Head gaskets, on the other hand, are not cheap to replace because you have to disassemble most of the engine to access the head gasket.

Damaged Radiator

Another reason why your car could be overheating is a damaged radiator. Your radiator helps cool off the engine coolant as it passes through the radiator. But if your radiator is damaged from an impact or from road debris then coolant won’t be able to pass through it to cool down. When this happens your radiator will need to be replaced with a new one, otherwise, your car’s engine will continue to overheat.

Plugged Heater Core

Your car heater core is used to provide heat to the interior of your car in the cold winter months. A heater core accomplishes this task by circulating hot engine coolant through the heater core which heats up the metal heater core. Outside air is then blown over the heater core which heats up the air surrounding the heater core, that hot air is then sent into the car interior to provide heat.

Heater cores can get plugged with debris in the coolant system which won’t allow coolant to circulate throughout the coolant system, at that point they would need to be cleared out or replaced to allow coolant to keep flowing to prevent your car from overheating.

Stuck Thermostat

The thermostat on your car is responsible for determining the temperatures of your coolant and either opening or closing to allow coolant to cycle through the engine. But car thermostats can get stuck open or closed which means that they will provide too much coolant to the engine or not allow coolant to cycle through the engine. Both scenarios are not good for an engine, but if your thermostat is stuck closed it can definitely be why your car is overheating.

Blown Head Gasket

A head gasket is designed to provide a seal between the engine block and cylinder heads of the engine. Over time an engine head gasket can be prone to cracking which can allow coolant and engine oil to mix which is not good news for your engine.

A blown head gasket can also cause engine coolant to leak out of the engine which can also be a contributing factor as to why you have low engine coolant and why your car is overheating.

Damaged Coolant Hose

Your car’s coolant system circulates coolant throughout the engine and back to the radiator through rubber coolant hoses. These rubber hoses can become brittle and crack over the years which will then allow engine coolant to leak out of the coolant or radiator hose onto the ground underneath the vehicle. If you notice that you have green or blue coolant underneath your car then most likely you have a damaged coolant hose.

Broken Radiator Fan

As you drive down the road outside air is passed through the radiator at the front of your car which helps to cool down the engine coolant as flows through all of the passageways of the radiator. But when you come to a stop fresh outside air won’t be passing through the radiator to keep it cool. That’s why your radiator will have fans on the back of them to keep cool air circulating through the radiator.

Radiator fans can fail over time, when this happens you will notice that your engine temperatures will climb as you come to a stop and then go back down as you are able to start moving again. If your car is overheating as I described above then you likely have a problem with your radiator fan and it may need to be replaced.

Faulty Water Pump

Your car’s coolant system works by pumping cold engine coolant through passageways in the engine to help cool it off. A water pump is used to pump cool coolant into the engine, warm coolant is then pumped back into the radiator to be cooled back off again, that cycle is then repeated over and over again.

Over the years your water pump can begin to fail because of broken fins in the pump or debris clogging up the water pump. When this happens your car will begin to overheat quickly because coolant won’t be able to circulate throughout the coolant system.

Clogged Coolant Hose

Another reason why your car is overheating is that it could have a clogged coolant hose. As I mentioned engine coolant needs to be circulated throughout the engine to cool it down. If you have a clogged coolant hose it won’t allow coolant to flow through the engine as well and can cause your car’s engine to overheat.

This problem can be trickier to spot than a leaking coolant hose because it’s a lot tougher to find a clogged coolant hose than a leaking coolant hose.

Symptoms of An Overheating Engine

Engine Temperature Gauge Shows High Temps

Obviously, if the temperature gauge on your dash is showing higher than normal temperatures then that’s a good indicator that your car’s engine is overheating. Your engine temperatures should sit around the middle of the temperature gauge when your car’s engine is running. If you notice that your engine temperatures are near the top of the temperature gauge then you’d want to turn off your engine to allow it to cool back down.

Temperature Warning Light

Most cars made today are sophisticated enough to know when their internal engine temps get too high. That’s why a lot of cars today will illuminate a temperature warning light on your dash indicating that the engine temperatures are higher than they should be. The temperature warning light will typically look like a thermometer and will be illuminated in red.

Steam From the Engine Bay

Another sign that your car is overheating is steam coming from the engine bay. If you notice steam rising up from your hood as your driving then it’s likely that there is a problem with your engine overheating. When you notice steam coming from your hood you would want to pull over to the side of the road and turn off your engine. Otherwise, you risk damaging your engine from excess heat.

Weird Smells From Engine Bay

Another symptom of an overheating car is weird smells coming from the engine bay. If after parking your car you smell some weird smells emanating from your car’s engine bay it could be cause for concern as your car’s engine could be overheating.

What Should You Do If Your Car Overheats?

Turn Off the AC

Your AC system is taxing on your car’s engine and should be turned off if you notice your car overheating. Doing so will take some stress off of the engine and allow it to cool down quicker.

Turn On the Heater

While turning on your heater during the hot summer months doesn’t sound like fun it can actually help your engine cool down by drawing heat away from the engine and into the cabin of your car. Obviously, if it’s hot outside you would want to roll down your windows when you do this otherwise the inside of your car will get very hot.

Pull Over and Open Hood

Pulling over and shutting off your car will also help cool down an overheated engine. Just be careful as the engine bay will likely be hot and rising steam can burn your face if you’re not careful.

*****An important word of caution is that you should never remove your radiator coolant cap when your engine is hot, doing so can allow hot engine coolant to shoot out of the radiator and onto you which can result in serious burns all over your face and body. *****

Drive Faster

Keeping moving or driving on the highway will keep air flowing through your radiator which will help cool down the engine coolant as it passes through the radiator. Sometimes you have to come to a stop but you’d want to avoid coming to a complete stop if possible so that your radiator has a constant flow of new air going through it.

Rev Your Engine

Revving your engine will make the water pump and radiator fan work faster which should help cool down the engine faster as long as there isn’t a problem with the water pump or radiator fan keeping them from working properly.

How Do You Fix An Overheating Car?

In order to fix your overheating car issue, you first need to pinpoint what is causing your car to overheat in the first place. Like I mentioned previously there are plenty of things that can go wrong with the coolant system on your car so you’d need to figure out what specific problems your car has and then work to fix them.

First, check your coolant levels (while the engine is cold) to make sure there is enough engine coolant in the coolant reservoir. Check your coolant hoses for cracks or leaks and replace them when necessary. Inspect the underside of your car for engine coolant that is leaking from the engine, radiator, or radiator hoses. Look at your radiator fan to make sure it’s still spinning, if not then it may need to be replaced.

There could also be issues that are not that easy to inspect visually, like problems with your thermostat, heater core, or head gasket. With these sorts of issues, you may need to take your car to a mechanic to have them diagnose the problem.

How Much Does It Cost To Fix An Overheating Engine?

The cost to fix an overheating engine will vary widely and will be determined what is actually causing the engine to overheat. Coolant hoses are inexpensive and can be found for less than $15.

Replacement engine coolant is also inexpensive to buy (usually less than $5) and can be used to fill up your coolant reservoir if it’s low on coolant. A new thermostat can cost anywhere from $40-$100 for the replacement part.

A blown head gasket is the most expensive of all of the repairs on this list and will typically cost thousands to repair because of the time it takes to access the head gasket to replace it. Some people will opt to replace their engine before having their head gasket replaced.

To learn more about what a head gasket does and why they are so expensive to replace check out my other article what does it mean to blow a head gasket.

How To Prevent Engine Overheating?

The best way to prevent your car’s engine from overheating is by making sure the coolant system of your car is functioning properly. That means repairing or fixing any issue that is causing the engine to heat up excessively. This ensures that your car’s coolant system will be able to keep the engine the engine cool and stop it from overheating in the first place.

Why Is My Car Overheating? Common Causes