Car Overheating: What Causes It and What to Do About It to Stay Safe

Let’s say it’s a hot summer day and you’re driving to the beach. It’s the weekend, so traffic is heavy. You’re singing along to your favorite song, trying to get in your own zone and forget about all those cars around you, and you’re feeling great.

All of a sudden, you notice a red check engine light on your dashboard. Buzzkill! You filled your gas tank, so that’s not the problem. What exactly is going on?

The warning light is telling you that the engine temperature is way too high. This means that your car is overheating. This is one of those situations where you really need to act act fast, or else bad things can (and will) happen.

There may be no obvious external signs which you should pay attention to, such as smoke coming out of the hood, but the temperature gauge going up into the danger zone should be enough to seriously worry you.

Young man inspecting the hood of his vehicle on the side of the road because of overheating problems

You cannot ignore it and drive on if you don’t want to end up with some major damage being dealt to your engine.

In this article, we’ll go through all the reasons why cars could possibly overheat, and we’ll go through everything you’ll need to do to fix this problem.

Before we get into all of that, though, we need to start with the clues that cars will often give away when engines overheat. To stay on top of the situation whenever it happens, you’ll need to know all the signs to watch out for, or else you’ll only be speculating at best.

Also, if you don’t act right away, you might end up with some serious damages that can sometimes be even more costly than the value of your car!

This is no joke, so you’ll need to be prepared beforehand and know exactly what to do immediately if you’re driving along and your car starts overheating. The sooner you act, the better, and we have you covered on all of that in the sections to come.

Ready? Let’s begin!

What Are the Signs That Your Car Is Overheating?

First things first, the following is a list of car overheating symptoms you should know about. Keep a close eye out for any of these issues, and act straight away if any of them come up at any point in time.

Unusually Hot Hood

The hood is normally hot after you’ve been driving, but if your car has overheating engine issues, then it will be hotter than usual.

In normal situations when overheating isn’t present, you should be able to place your hand on the hood for at least 10 seconds without burning yourself. If you cannot even touch it and the hood is unusually hot, then you can be sure that something is definitely wrong.

Please be careful if you do place your hand on your hood, as you can seriously hurt yourself if overheating problems are present.

For safety purposes, use the back of the hand to prevent your palm from burning, and always assume that you’re going to be touching something incredibly hot.

Warning Light

Your temperature gauge will reach dangerously high levels. Normal temperatures range from 195 to 220 degrees Fahrenheit. If it’s higher, you should see the warning light come on.

Do your car and yourself a favor: don’t ignore it!

Ticking Noises

This indicates that the engine is too hot. It means the oil is overheating and is not doing its lubricating job well.

Burning Smell

If your car overheats, you may smell burning oil, rubber or plastic. This is a sure sign that the engine is overheated.

Thumping Noises

This happens when a valve is blocked due to too much heat. Cold coolant tries to mix with super hot coolant, and the thermostat will usually need to be replaced in this case.

Steam out of the Hood

This is a pretty obvious sign, and you need to pull over right away the very instant it happens.

It means the engine coolant has reached boiling temperature and is overflowing.

Visible Leaks

If there are visible leaks, such as liquid under your car, it means the coolant flow is excessive.

Don’t mistake the coolant leak for an oil leak, though. If in doubt, call a professional and ask for their opinion.

Engine Power Loss

If your engine feels like it’s not as powerful as usual, it means something is wrong. There are many causes of reduced engine power, and overheating is one of them.

If your car gives you any of these warning signs, don’t wait to get it checked – do it straight away as soon as you get a chance to.

You may end up saving yourself thousands of dollars in the process, and saving your car too!

What to do if Your Car Overheats?

Now you know about all the warning signs of an overheating vehicle, let’s go over what you need to do right away if you ever find yourself in such a situation.

Turn the AC Off

Cars often overheat in hot weather, so the first thing to do is immediately turn the AC off.

Turn Defrost Button on and Put Heat on High

Even though this sounds crazy and counter-effective, but the heater will pull as much heat out of your engine as possible.

It might make all the difference in the world when trying to save your car.

Roll Down the Car Windows

The temperature inside the car should be hotter than that on the outside.

You’ll probably not be comfortable if you roll down your car windows and let all that heat it, but it’s worth being hot for a while to save your engine.

If You’re Not Moving

If you’re bottled up in traffic and not moving, switch your gear to neutral or park. Push the gas pedal to keep your RPM range around 2000.

If You’re Moving

If you’re driving along, even if you’re just doing so slowly, use the lowest gear to keep your RPM range between 2000 and 3000.

Keep Speed Constant

If you can do this at all, try to keep your speed constant instead of stopping and starting. This will keep your engine cooler.

Pull Over

As soon as you get a chance to do so, pull over and call for help.

Do not try to drive to the nearest gas station if your car is overheating. The sooner you turn off the engine, the better the chances of not creating huge damage which you’ll regret later.

Open the Hood

As soon as you’re safely off the road, open the hood to let the engine cool off. Before stopping the car and popping the hood somewhere, be aware that this may take anywhere from 20–40 minutes.

Check Radiator Hoses

Be extra careful when doing this, as they will be scorching hot!

Use a rag or towel and just squeeze the radiator hoses. If they’re stiff, it means they’re pressurized. You’ll need to wait until the pressure goes down to open the radiator cap.

Open the Radiator Cap

If the car is hot, the pressure inside will be high. Be very careful, you don’t want to get burned!

Only open when pressure is down to normal again.

Check Coolant

In most modern cars of today, you’ll have a separate coolant tank.

Check the coolant level in the tank. If you have low coolant levels, add some. It is safe to do so even when the car is hot, provided that it is separate from your radiator.

For further details, check out guide on how to change coolant, that includes topping up.

Wait for Help

Don’t just wait until the engine is cool and drive on. It’s better to first wait for a professional to check your car if you’re not able to do it yourself.

Common Reasons Why Your Car Overheats

Now that we’ve covered what you should do to save your engine when your car overheats, let’s go over the many possible reasons a car overheats in the first place, and what steps you can take to fix it.

Leaks in the Cooling System

This is the most common reason that causes an engine to overheat. If the coolant leaks, it cannot do its job properly.

Leaks are potentially due to a hole, or are just down to normal wear and tear. If you have to add coolant often, it’s a sign that there is a leak somewhere.

Coolant Combination

The coolant or antifreeze you used may not be the right type for your vehicle. Or, it may not be combined in the proper ratio with distilled water.

In both cases, this can cause your car to overheat.

Coolant must be replaced in due time, or it becomes corrosive. It’s also toxic, so handle it carefully!

Thermostat Not Working

If you have a stuck thermostat and it becomes blocked in the closed position, it does not allow coolant to pass. This means the engine becomes overheated.

Failing Radiator

If your radiator is not working properly, it cannot take off the heat, leading to the engine overheating.

Cracked or Old Hoses

If your hoses aren’t in good condition, your engine will leak. Coolant will not reach the engine properly.

Failing Radiator Fan

The fan pushes air on the radiator to cool it. If it’s not working as it should, perhaps because of a failing fan motor, it leads to overheating.

Water Pump Belt Failing

If the water pump belt is not working, the coolant will not flow to cool the engine.

Broken Water Pump

The water pump is the protagonist when it comes to your car’s cooling system. If the pump doesn’t work perfectly fine, the coolant will not be able to reach your engine.

As a safety rule of thumb, water pumps should be replaced after around 100,000 miles.

Blockage in Cooling System

Usually, bad-quality coolant freezes in cold weather. This may create blockages that lead to the car overheating.

Oil Level

This is another common cause of overheating, even though not many car owners are aware of it.

The oil lubricates the engine, but it is also responsible for removing 70% to 85% of heat from the engine. Make sure you engine has enough by checking the oil level.

If you need to refill your car’s oil often, there could be a leak. Older cars tend to use up oil faster, even without any leaks.

Head Gasket Malfunction

If the gasket has issues, such as when you have a blown head gasket, it may cause the coolant to leak into the oil circulatory channels of the car.

This could cause the premature death of your car.

Air in the Coolant Lines

This causes the engine to not have enough coolant to properly lower the temperature.

Radiator Is Too Small

If the radiator is too small, your car will only overheat when driving fast and hard.

To stay on the safe side of things, you will need to replace it with a more powerful model.

Faulty Warning Light

The temperature gauge could be faulty if it signals a high temperature.

However, the best practice is to assume that it’s something to do with your car overheating. It’s not worth the risk to assume otherwise.

Hot Weather

Modern cars are equipped with cooling systems that do not fear hot weather.

On the other hand, classic cars are a completely different story. They do not have a liquid cooling system, so they may overheat simply due to high outside temperatures which they can’t handle. This could happen even if there are no issues with any parts of the engine at the time.

The best thing to do in this case is to get your car towed to a service station as soon as possible. Stay on the safe side and stop as soon as possible if your car starts overheating – don’t risk driving any further unless you absolutely must do so.

If you do that, then chances are you won’t have caused any major damage to the engine.

Tips to Prevent Your Car From Overheating

You know what they always say about how prevention is the best medicine? This can’t be any more true here. Instead of having to deal with an overheating car on your hands, prevent it from happening in the first place.

Sure, this isn’t always possible, but there’s still a whole lot you can do to keep such a problem at bay.

Here are a few helpful tips you should always keep in mind to prevent your car from overheating:

  • Always check your temperature gauge.
  • Check oil levels frequently.
  • Flush and clean your radiator, and ensure that it’s working efficiently at all times.
  • Exhaust wrap. This is a protection you can apply that prevents heat from reaching the engine.
  • Try to avoid rush hour traffic. Steady, constant driving is less likely to cause overheating.
  • Park in the shade whenever possible.
  • Use a sunshade to keep your car cool.
  • Tint your windows. Tinted windows keep the inside of your car cooler. Make sure you check the laws regulating them in your state, just to stay outside of trouble and not unknowingly break the law.
  • Leave your car windows open a crack for ventilation when you park.
  • Turn floor vents on. Hot air rises, so first use floor vents to cool the car.
  • Turn off the recirculation button until the car is cool.
  • Replace your car battery regularly.
  • Always keep some spare coolant in the car.
  • Service your car regularly. Most overheating issues are caused by poor maintenance!

Common Damages Caused by Your Car Overheating

Just in case you thought that driving with an overheating car is not that much of a big deal, think again! This is a very serious situation that needs your attention straight away.

You could end up having to scrap your car if the damage is too extreme. If not, here are some damages that can result from a car overheating:

The Engine Can Die on You

If this happens in traffic, and your car stalls suddenly, you can risk an accident, especially if you’re on a highway and driving at a high speed.

This is a prime example of a situation you don’t want to find yourself in, one that can unfortunately prove to be fatal.

Damage to Gaskets and Seals

Car repairs, in this case, could cost between $1000 and $2000. This figure could be even greater if your car has two engine heads.

Not exactly a sum you look forward to paying for something that can be avoided, right? This is especially true since it’s damage you can avoid easily by not driving a car that is overheating.

Loss of Power

Similar to your car stalling, the engine losing power will also put you at risk. Your car will not react as quickly as it should in these cases, especially in a situation when you need full power, such as when passing another car.

Damage to Pistons and Cylinders

Repairs for your pistons and cylinders can cost between $900 and $1800, depending on the type of car you’re driving. The entire engine must be disassembled in this situation.

This is another easily avoidable expense.

Heat Can Warp the Metal of Cylinder Heads

Repairs will cost at least $500, and sometimes up to $1000. Surely you have better ways to spend this money, no?

Worst Case Scenario, the Radiator Can Explode!

This is probably not the time to delight in the loud sound of fireworks resonating from under your hood and the column of smoke that follows.

This is a serious situation, your car will stall and you’ll be stuck waiting for help. You’ll also be looking at at least $500 in damages.

Final Thoughts

As you can already tell by now, your car overheating is serious business.

If you ignore the signs and choose to drive on because you think it’s not that big of a deal, you may end up completely ruining your car’s engine. Repairs may even exceed the value of your car altogether – not something you’ll look forward to, that’s for sure!

We hope this article managed to shed some light on the importance of never underestimating a car that’s overheating.

I personally know of an individual who used to drive a 1978 Renault 5. In the peak of summer, he was forced to keep the heat on full blast.

It was the only way to avoid the water in the radiator from boiling over. This would have meant a huge column of steam flying out of the hood.

It only happened when the car was idle for too long, so he had to drive much longer distances to avoid traffic. Way to turn a car drive into a sauna and Turkish bath in one go!

Humor aside, the best way to avoid this emergency situation is to service your car regularly. Most experts agree that a car overheats when the owner does not maintain it properly.

This is both good and bad news. It’s good news because all you need to do is be diligent about car check-ups and you should be fine, and it’s bad news if you’re not conscientious enough and tend to skip on routine scheduled maintenance; something most of us have been guilty of at one point or another in our lives.

Do you have any experience with an overheating car? Did it ever happen to you? Did you wish you had read this article before it happened to you? We’d love to hear your stories and experiences, so please let us know about all of them in the comments!

From childhood go karting and motocross, to collecting and obsessing over scalextric, matchbox and radio controlled cars, I've always had an obsession with cars. Learning through manuals, books, trial and error, and more knowledgeable family members, I've also enjoyed tinkering with the mechanics and electronics of any vehicles I've owned. Now, over 3 decades later, I've started this site as a place for me to share my knowledge, to teach others how to care for and maintain their vehicles themselves, at home, so they can get the most of their vehicles and save a pretty penny compared to always seeking out professional help.

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