Car Engine Overheating?: Signs, Causes, Fixes, and Avoidance
All of a sudden, you notice a red engine light on your dashboard!
Overheating vehicles are a common issue and can lead to costly repairs, or the premature death of your car, if left unresolved. Cars can overheat for several reasons and several symptoms will let you know when all’s not well under the hood.
In some cases, you can address the problem yourself; in others, you’ll need a professional to save your vehicle from further damage.
In this post, we reveal all you need to know about overheating car engines. After going through the signs and causes of a car overheating, we’ll then delve into what to do when it happens and how you can avoid it in the first place.
Ready? Let’s begin!
Contents (Jump to Topic)
- 1 Car Engine Overheating?: Signs, Causes, Fixes, and Avoidance
- 2 Key Takeaways
- 3 What Are the Signs That Your Car Is Overheating?
- 4 What to do if Your Car Overheats?
- 4.1 1. Turn the AC Off
- 4.2 2. Turn Defrost Button on and Put Heat on High
- 4.3 3. Roll Down the Windows
- 4.4 4. If You’re Not Moving
- 4.5 5. If You’re Moving
- 4.6 6. Keep Speed Constant
- 4.7 7. Pull Over
- 4.8 8. Open the Hood
- 4.9 9. Check Radiator Hoses
- 4.10 10. Open the Radiator Cap
- 4.11 11. Check Coolant
- 4.12 12. Wait for Help
- 5 Common Reasons Why Your Car Engine Is Overheating
- 5.1 1. Cooling System Leak
- 5.2 2. Coolant Combination
- 5.3 3. Thermostat Not Working
- 5.4 4. Failing Radiator
- 5.5 5. Cracked or Old Hoses
- 5.6 6. Failing Radiator Fan
- 5.7 7. Water Pump Belt Failing
- 5.8 8. Broken Water Pump
- 5.9 9. Blockage in Cooling System
- 5.10 10. Oil Level
- 5.11 11. Head Gasket Malfunction
- 5.12 12. Air in the Coolant Lines
- 5.13 13. Radiator Is Too Small
- 5.14 14. Faulty Warning Light
- 5.15 15. Hot Weather
- 6 Tips to Prevent Your Car From Overheating
- 7 Common Damages Caused by Your Car Overheating
- 8 Final Thoughts
Stop Driving! – An overheated engine can be very dangerous, so pull over immediately if you see any symptoms
Multiple Causes – Car engines overheat for various reasons – we’ve added a comprehensive list of potential causes below.
Prevention Is Preferable – To avoid engine overheating (and racking up the resultant bills), it’s best to have your vehicle serviced regularly
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.
1. Unusually Hot Hood
The hood is normally hot after you’ve been driving, but if your vehicle has overheating engine issues, then it will be hotter than usual.
You should be able to place your hand on the hood for 10 seconds without burning yourself. If you can’t, then something is definitely wrong.
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.
2. Warning Light
Your engine 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!
Engine temperature gauge symbols vary from car to car, so check your owner’s manual.
3. Ticking Noises
This indicates that the engine is too hot. It means the engine oil is overheating and is not doing its lubricating job well.
4. Burning Smell
If your car overheats, you may smell burning oil, rubber, or plastic.
5. 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 car thermostat will usually need to be replaced in this case.
6. Steam out of the Hood
This is a pretty obvious sign, and you need to pull over right away if it happens.
It means the engine coolant has reached boiling temperature and is overflowing the coolant reservoir tank.
Alternatively, your overheating engine may have boiled your radiator fluid, which will escape from under your hood as steam, vapor, or white smoke.
7. 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.
8. Engine Power Loss
If your engine feels like it’s not as powerful as usual, 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, get it checked straight away. 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.
1. Turn the AC Off
Cars often overheat in hot weather, so the first thing to do is immediately turn off the Air Conditioning.
2. Turn Defrost Button on and Put Heat on High
This sounds crazy and counterintuitive, but the heater will pull as much heat out of your engine as possible.
3. Roll Down the Windows
You’ll probably not be comfortable if you roll down your windows and let all that heat it, but it’s worth being hot for a while to save your engine.
4. 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.
5. 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.
6. Keep Speed Constant
Try to keep your speed constant instead of stopping and starting. This will keep your engine cooler.
7. Pull Over
As soon as possible, pull over and call for help.
Do not try to drive to the nearest repair shop or gas station if your vehicle is overheating. The sooner you turn off the engine, the better the chances of not creating huge damage you’ll regret later.
8. Open the Hood
As soon as you’re safely off the road, open the hood to let the engine cool off. This may take anywhere from 20–40 minutes.
9. 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.
10. 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.
11. 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 engine is hot, provided that it is separate from your radiator.
For further details, check out our guide on how to change coolant.
12. 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 vehicle if you’re not able to do it yourself.
Common Reasons Why Your Car Engine Is Overheating
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 an engine overheats in the first place, and what steps you can take to fix it.
1. Cooling System Leak
This is the most common reason that causes a car to overheat. If the coolant leaks, it cannot do its job properly.
Leaking coolant may be caused by a hole, damaged coolant hoses, or just normal wear and tear. If you have to add coolant often, it’s a sign that there is a leak somewhere.
2. Coolant Combination
The new 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 vehicle to overheat.
Coolant must be replaced in due time, or it becomes corrosive. It’s also toxic, so handle it carefully!
3. 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.
4. Failing Radiator
If your radiator is not working properly, it cannot take off the heat, leading to the engine overheating.
5. Cracked or Old Hoses
If your hoses aren’t in good condition, your engine will leak. Coolant will not reach the engine properly.
6. Failing Radiator Fan
The cooling 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.
7. Water Pump Belt Failing
If the water pump belt is not working, the coolant will not flow to cool the engine.
8. 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.
9. Blockage in Cooling System
Usually, bad-quality coolant freezes in cold weather. This may create blockages that lead to overheating.
10. Oil Level
Motor oil lubricates the engine, but it is also responsible for removing 70% to 85% of heat from the engine. Make sure your engine has enough by checking the oil level.
If you need to refill your engine oil often, there could be a leak.
11. 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 vehicle.
This could cause the premature death of your ride.
12. Air in the Coolant Lines
This causes the engine to not have enough coolant flowing to properly lower the temperature.
13. Radiator Is Too Small
If the radiator is too small, your engine will only overheat when driving fast and hard.
To stay safe, you will need to replace it with a more powerful model.
14. 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.
15. Hot Weather
Modern cars are equipped with cooling systems that dissipate heat well in hot weather.
Classic cars are a different story. They do not have a liquid cooling system, so they may overheat simply due to high outside temperatures.
The best thing to do in this case is to stop and get your vehicle towed to a service station as soon as possible.
Tips to Prevent Your Car From Overheating
They say prevention is the best medicine. This can’t be any more true here. Instead of having to deal with an overheating vehicle, 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 to prevent your car 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.
- 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 vehicle cool.
- Tint your windows (check the laws regulating them in your state first)
- Leave your windows open a crack for ventilation when you park.
- Turn floor vents on.
- Turn off the recirculation button until the car is cool.
- Replace your battery regularly.
- Keep spare coolant in your vehicle.
- Service your vehicle 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 vehicle is not that much of a big deal, think again! This is a very serious situation that needs your attention straight away.
1. The Engine Can Die on You
If this happens in traffic, you can risk an accident, especially if you’re on a highway and driving at high speed.
2. Damage to Gaskets and Seals
Repairs, in this case, could cost between $1000 and $2000. This figure could be even greater if your vehicle has two engine heads.
3. Loss of Power
Similar to your vehicle stalling, the engine losing power will also put you at risk. Your car will not react as quickly as it should, especially in a situation when you need full power, such as when passing another vehicle.
4. Damage to Pistons and Cylinders
Repairs for your pistons and cylinders can cost between $900 and $1800, depending on the type of vehicle you’re driving. The entire engine must be disassembled in this situation.
5. Warped Metal on Cylinder Heads
Repairs will cost at least $500, and sometimes up to $1000. Surely you have better ways to spend this money, no?
6. The Radiator Can Explode!
This is a serious situation, your vehicle will stall and you’ll be stuck waiting for help. You’ll also be looking at at least $500 in damages.
As you can already tell by now, your car overheating is serious business.
If you ignore the signs and choose to drive on, you may end up completely ruining your car’s engine. Repairs may even exceed the value of your vehicle altogether – not something you’ll look forward to!
We hope this article managed to shed some light on the importance of never underestimating a vehicle that’s overheating.
Do you have any experience with an overheating car? We’d love to hear your stories and experiences, so please let us know about all of them in the comments!