How to Tell if Your Car is Overheating (5 Signs)

Close up of a car engine glowing red due to overheating

If you know anything about cars, then you surely know that the last thing you want your car to do is overheat. When your car overheats it means that your car’s engine isn’t being cooled properly. This is a big issue because it can cause severe damage to your engine. 

There are certain indicators that will let you know your vehicle’s engine is overheating. Listed below are the most common way to identify if the engine is overheating:

  • Temperature Gauge
  • Unfamiliar Burning Smell
  • Smoke Coming From the Hood
  • Leaking Radiator
  • Hot Hood

When you consider the fact that replacing a car’s engine is one of the most expensive repairs out there, it makes sense to be aware of possible signs of overheating. 

5 Signs Your Car is Overheating

If you don’t already know what signs to look out for to ensure that your car isn’t overheating, then you should look at the sections below to find more information on what you should be looking out for. 

#1 – Temperature Gauge

Perhaps one of the most obvious signs to look out for is to simply look at the temperature gauge on your dashboard. You should make sure that the gauge isn’t reaching the maximum level as that would indicate that your engine is overheating.

The temperature gauge is there to display the amount of heat in the engine. Many people believe that you need to let your car engine warm up before driving which can be done by simply looking at the temperature gauge and seeing it go up before you begin driving. 

However, there can sometimes be issues with the temperature gauge that could lead you to miss other possible signs that your engine is overheating. For starters, the temperature gauge measures the temperature of the coolant in the engine. This means that if your car has a substantially large coolant leak, the temperature gauge would fail to read the excess heat in your car’s engine. 

In addition, there can be other things that go wrong with the temperature gauge that could cause it to display inaccurate information. Although it is the first thing you should look at when trying to determine if your engine is overheating, it should not be the only thing you look for. 

Close up of a engine temperature gauge showing overheating in red with an overheating diagnostic light on

#2 – Unfamiliar Burning Smell

Another sign that is a little more unfamiliar is to look out for a smell coming from your car. This can be helpful but it can also be hard to use this as a sign if you have never actually smelled what an overheating car smells like.

When your car’s engine begins to overheat, the oil inside of the engine as well as the plastic sealants and valves will begin to burn and in some cases melt. The burning and melting of these materials produce a peculiar smell that can be used as a sign of an overheating engine. 

Unfortunately, if you can smell the burning of your engine, there is probably a substantial amount of damage done to your engine. However, it is still better to realize that your engine is overheating and pullover rather than just continuing to drive until your car finally breaks down. 

Driver holding his nose detecting a burning smell coming from the vents of the car possibly due to engine overheating

#3 – Steam or Smoke is Coming From the Hood

Steam or smoke coming from the hood of your car is the most obvious sign that your car is overheating. If this happens to you, you need to pull over and shut off your car as soon as possible as this is very dangerous.  

When steam is coming from underneath your hood it means that your car is already overheated. The quicker you immediately pull over the fewer chances of something being permanently damaged inside your engine. The oil and other materials inside the engine have already started to burn and melt which will continue to happen and could escalate to cause a fire.

Honestly, this is the last thing you want to see while you are driving. However, if this does happen to your car while you are driving know that the only thing you can do is pull over to the side of the road, turn the engine off, and wait for it to cool. Once your engine has reached the point where steam is coming from under the hood it is going to take a while, maybe even hours, for it to cool off.

You should probably also call someone you know to come and pick you up. As well as a tow truck because once your engine overheats it is much more likely to do it again until you address the underlying problem.

Person opening the car hood after noticing steam smoke coming from the hood

#4 – Leaking Radiator

One of the many reasons why your car might overheat is due to a leaking radiator. This is one of the most common reasons why car engines overheat, but it doesn’t mean that you should continue to drive once the temperature sign flashes on your dash just because it is common. 

The radiator is the part in charge of cooling the engine. The radiator cools the engine when the temperature gauge detects that there is excess heat in the engine that needs to be removed. After this happens, coolant and water are released in order to reduce the temperature of the engine. 

When your radiator leaks, all of the coolant in the radiator that is needed to maintain a safe temperature in your engine begins to leak. If you don’t realize that you have a leak in your radiator you might end up driving for much longer than you should and cause your car to overheat. 

If you realize that there is a puddle of coolant underneath your car before you start driving, you should add more coolant. However, this is only a temporary fix as you will more than likely have to get the radiator replaced in order to fix the leak. If you are in a rush, you can simply add more coolant until you can get a replacement radiator. 

Radiators in modern cars usually last for around 150,000 so it is not something that you typically have to replace. The typical price to replace a radiator ranges from $1,000 to $3,500. Although it is expensive, it is much cheaper compared to having to fix your engine after overheating which can cost anywhere from $3,000 to $5,000. 

Close up of green fluorescent coolant liquid leaked out from the

#5 – Hot Hood

One way that you can tell if your car is overheating is by feeling the temperature of your car’s hood. This isn’t necessarily the best way to tell if your engine is overheating or not, but it can be helpful.

Whenever your car’s engine is on, the hood of your car will naturally warm up. However, it shouldn’t be so hot that it burns your hand when you touch it. You should be able to comfortably place your hand in your car’s hood for at least 10 seconds under normal conditions.

If for whatever reason, your car’s hood is so hot that you can’t put your hand on it for at least 10 seconds, you should check to see that the temperature gauge in your car shows that your engine isn’t overheating. 

Blue Car hood glowing red hot due to engine overheating illustration

Reasons Why Car Engines Overheat

Now that you know some of the signs of an overheating engine, you might be wondering what can cause a car engine to overheat and what you can do to prevent it from happening. 

There are a variety of reasons why an engine might overheat while you are driving such as bad coolant, radiator issues, or water pump issues. Many of the reasons are problems that are out of your control which you can’t really check for before you begin your drive.

However, there are some issues, like bad coolant, that can be avoided by properly caring for and maintaining your vehicle. Below are some of the most common reasons why a car may overheat and what you can do to prevent it from happening.

Bad Coolant Mixture

One thing that can cause your engine to overheat is having a bad or old coolant mixture. This is different and much less obvious than having a coolant leak which is also a major reason why car engines overheat. 

If you never flush out or change the coolant mixture in your engine, then as time passes it may become more corrosive which will cause it to do more harm than good to your engine. This is an issue that is very difficult to see with the naked eye and you will likely not notice it until after it begins to cause problems.

To prevent your coolant mixture from getting too old or going bad, it is recommended that you flush it out approximately every 30,000 miles or every 3 years. If you are someone that drives a lot, you are going to want to change it every 30,000 miles. However, if you don’t really drive your car that much, you are still going to want to flush it out around every 3 years or so. 

Another issue that can cause the engine to overheat that also has to do with the coolant mixture is putting the wrong coolant-to-water ratio into your mixture. The correct ratio will vary depending on the type of coolant you are using since some cars use special coolants while others just use regular ones. 

If you are changing out the coolant yourself, you should check the label of the bottle or the instructions in your owner’s manual to make sure that you know the correct coolant to water mixture and avoid any issues with that. 

Pouring anti-freeze engine coolant into the reservoir

Radiator Issues

As mentioned earlier, the radiator plays a pretty important role when it comes to making sure that your engine doesn’t overheat. Naturally, if there is an issue with your radiator, it can lead to issues in your engine such as overheating. One issue that can take place in your radiator is having a faulty fan.

The radiator relies on an electrical system to turn on the fans that it uses to remove the excess heat that is generated by the engine. There are many components in this electrical system that can wear out and fail which can lead to the fan not kicking in. 

For example, experiencing any issues with the wiring or fuses within the electrical system of the radiator can cause the fan to not turn on when needed. As you can probably imagine if the fan doesn’t turn on your car is much more likely to overheat since the radiator isn’t working properly. 

In addition, although it is very rare for the motor fan to go bad itself, it is also a possibility. Either way, regardless of whether the fan goes bad on its own or it is an issue with the electrical system, both of these issues will likely result in your engine overheating. 

Engine Cooling System Illustration

There are other issues that can take place with your radiator that can lead to overheating such as:

  • Rust
  • Corrosion
  • Clogs
  • Leaks

All of these issues will lead to your radiator not properly doing its job which typically results in your engine overheating. 

The worst part about experiencing radiator issues is that there is not really much that you can do to prevent it from happening. It is also very hard to detect issues with your radiator until it leads to a problem such as your engine overheating. 

Although there isn’t much you can do to prevent these issues from happening, the best thing you can do is take your car to get it serviced at regular intervals per car manufacturing recommendation. If there are any clear issues with your radiator the mechanics will probably be able to detect them when you are getting your car serviced. 

After reading about all of the possible things that can go wrong with your radiator, and how little you can do to prevent them, you might be feeling a little hopeless. However, the good news is that radiator issues don’t tend to happen too often. When these issues do happen, you more than likely have to get a new radiator but that generally puts an end to these issues. 

The good thing is that radiators last for a really long time, so unless you have been driving the same car for decades, you probably won’t have to replace your radiator more than once and even then you might not need to replace it at all depending on the amount of care you put into your car and how many miles you drive it for. 

Clogged aluminum radiator with dirt and debris visible on the radiator causing air conditioning and engine cooling issues
Clogged aluminum radiator with dirt and debris

Water Pump Issues

The water pump and the belt also play a major role in your engine’s coolant system. However, these are often the most overlooked when it comes to preventing your car’s engine from overheating.

As the name suggests, the water pump is tasked with pumping water into the engine in order to cool it along with the coolant. If there is an issue with the water pump and water is unable to reach the engine, then the engine will more than likely overheat and begin to show some of the signs mentioned above. 

There isn’t really much that you can do at home to make sure that the water pump and belt are functioning properly. Whenever you take your car to get serviced they should be checking to make sure that the water pump and the belt are functioning properly. 

As long as you make sure that you take your car to get serviced when you are supposed to and listen to the warnings that the dashboard may give you regarding regular servicing, you should be good to go.  

It can be pretty easy to think that the mechanics at the shop are just trying to get you to pay them to repair something that isn’t broken. At the end of the day, nobody likes to pay for repairs they don’t need. However, if you choose to ignore the advice of your mechanics, it can lead to a much more costly repair especially when talking about engine overheating. 

Getting a water pump replaced costs around $500, meanwhile fixing your engine after it overheats can cost well into the thousands of dollars. This is why if your mechanic tells you that you need to get your water pump replaced, you should listen to them. 

It is much better to bite the bullet and spend the $500 replacing a water pump than having your engine overheat and having to pay thousands and have it sitting at the shop for a couple of weeks while the engine is fixed or a new one is installed. 

Comparing an old vs new car water pump

Solutions When Your Car is Overheating

Alright so now you know what signs to look out for when trying to figure out if your car is overheating. You also now know what might cause your car to overheat, but you might be wondering what solutions exist for when your car is overheating.

There are a handful of things that you can do when your car is overheating. Most of them are pretty simple and easy to follow. The most important thing when your car is overheating is to act quickly because the more time you drive with an overheating engine the worse the damage will be. 

Pull Over

The best thing you can do when you realize that your car is overheating regardless of which one of the signs listed above you recognize is to pull over immediately. 

The longer you drive with an overheated engine the worse the damage will be. This is why the number one solution to an overheating engine is pulling over and turning the engine off. 

Once you have pulled over and turned the engine off you will have to wait for the engine to cool down. You need to be patient whenever this happens. Once the engine gets to a point where it is overheating it is going to take a while to cool back down. 

After the car has cooled down, probably the best thing you can do is take your car to your mechanic or dealership to get serviced. As you probably know by now, overheating engines don’t just happen due to bad luck. If your engine overheats there is something wrong with your car that needs to be fixed at a dealership or mechanic shop. 

If you want to be even more cautious, then you should probably just call a tow truck to tow your car to the dealership or mechanic shop to get serviced. Once a car engine overheats it is more likely to do it again if you try to drive it immediately after. Although it is understandable to try to drive your car to the dealership yourself to save some money, it might end up costing you a lot more by increasing the severity of the damage to your engine. 

Woman calling on a smartphone for assistance after her car broke down with a triangle emergency sign visible

Turn on the Heater

Although it might sound like a really dumb idea to turn your car heater on when the engine is overheating, it is actually a good solution whenever your car overheats. 

The heater in your car that you use in the winter to keep you warm as you drive gets the heat from the engine. This heater pulls heat away from the engine and brings it to the inside of the car to keep you and your passengers warm. 

This is why turning your heater on when your engine is overheating is a good idea since it draws heat away from the engine. However, you shouldn’t think that simply turning on the heater will solve the issue. The truth is that the only thing that will solve the issue is taking your car to a service station. In the meantime, turning on the heater can help you reduce the heat in the engine and thus the damage. 

Close up of a hand turning on the heater on the HVAC climate control of the car by turning the knob

Conclusion

There are several signs that you can look out for when it comes to making sure that your engine doesn’t overheat. An overheating engine is one of the worst things that can happen because of how expensive it can be to fix and how difficult it can be to prevent. 

Hopefully, after reading the information in this article you have picked up on some of the tips on how to tell if your engine is overheating and what to do if it does. It is extremely easy to panic whenever you see steam coming from under your hood which is why it is important to know the signs of an overheating engine and what you can do to mitigate the issue. 

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References:

Motor Hills

Natrad

Sun West Transmissions & Radiators

Bowers Automotive

Warning Signs that Your Engine is Overheating

Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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