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Car Overheating? What To Do When Your Engine Temp Spikes

Stay Calm And Be Prepared With These Tips For Dealing With an Overheating Car

car overheating

Many of today’s cars are models of technological wizardry, but that doesn’t mean they can’t overheat from time to time. And if you have an older vehicle or a modified car (perhaps one you like to take on a spirited drive now and then) and live in an area with toasty temps in the summer, you may one day find your car overheating while you are on the road. Here are the signs to watch for and what to do if your car is overheating.

Signs of a Car Overheating

Your engine has an optimal operating temperature range. Once your car has been turned on and the engine warms up, a normal operating temperature for most engines is roughly between 195 and 220 degrees Fahrenheit or 90 to 105 degrees Celsius. Temperatures above the high end of this range can signal trouble.

And though you might be tempted to keep driving when your engine is running a little hot, be aware that driving an overheating car even a short distance can cause expensive damage to your engine. Continuing to drive a car with an overheating engine can result in damage like broken hoses, warped cylinder heads, and, in the worst-case scenario, a blown head gasket or cracked engine block. Luckily, by being on the lookout for the following signs and addressing a rising temperature as soon as you identify it, you should be able to avoid these issues.

A Rising Temperature Gauge

If the temperature gauge on your dashboard is creeping higher, then that’s a sign of an overheating car. While your car will run hotter during warm weather, if the gauge hits the red zone or warning lights illuminate, then your engine is overheating.

Most older vehicles have a needle gauge showing an approximate temperature with an upper limit marked in red on the dial. Some newer vehicle models lack this needle gauge and instead utilize a warning light to alert you when your engine temp is above safe operating temperatures.

Another feature found on some newer vehicle models is “limp mode.” This self-protective setting may turn on if sensors indicate the car is overheating. Once the computer system activates “limp mode,” it will reduce the power to lessen the load on your engine—you’ll still be able to drive the car, but it will feel underpowered and sluggish.

Steam Under the Hood

If you see something that looks like smoke (a scary thought) coming from your engine bay, it may actually be steam from a coolant leak. As your engine temps rise, your coolant gets extremely hot (and could even boil), putting a lot of stress on your hoses and hose junctions. A steady stream of steam usually indicates a slower leak, but a sudden burst could mean you just blew a hose.

What’s That Smell?

Notice a weirdly sweet smell? That’s probably a coolant leak. If the smell is more like something burning, you might be dealing with an oil leak. Both types of leaks can lead to your car overheating. Either way, if you smell an unusual, persistent smell coming from your vehicle, it’s best to check it out.

What You Should Do For An Overheating Car

When you notice your temperature gauge creeping into the red, this could be a sign of trouble. You definitely don’t want to ignore your car overheating, which can lead to irreversible engine damage, but what should you do next once you notice that your engine is getting hot?

Don’t Panic

This may seem like easy advice, but panic isn’t an unreasonable response when your car is spewing steam, smells funny, and the temperature gauge is steadily creeping higher. Instead, take a deep breath, find a safe spot to pull over, and then assess the situation.

Turn on The Heater

This might seem counterintuitive. When your car is overheating, why would you want more heat? While turning on the heater will make the passenger compartment warmer, it will also draw heat away from your engine to make it cooler. This is an excellent move if you need to drive for a little way to find a safe place to pull off the road. Turn off the A/C and crank the heat.

Pull Over And Turn Off the Engine

The best way to cool down an overheating engine is to turn it off. This will bring down the temperature and prevent engine damage. Make sure you choose someplace safe where there’s plenty of room to get out of the flow of traffic and safely exit the vehicle.

Don’t Immediately Pop the Hood When the Car is Overheating

Popping the hood will improve the flow of cooler air to your engine, but it could also be dangerous. The hood and latch may be extremely hot and may burn your hands. If you notice steam escaping under the hood, you risk that steam or even boiling coolant spraying out and causing burns.

Wait for at least 15 minutes for the engine and engine bay to cool down a bit before you open the hood. Even then, do so cautiously. If you have protective gear like gloves or goggles in your trunk, now’s the time to put them to good use.

Top Off the Engine Coolant

Once your engine has had a chance to cool down, check the engine coolant levels. If your coolant level is low and you don’t have any obvious coolant leaks or blown hoses, you can try adding additional coolant. We can’t say it enough — be careful. An overheating engine is going to be hot even after you’ve let it sit for 15 minutes.

Start by wearing gloves and goggles, too, if you have them, and finding a towel or thick rag. Place the towel over the radiator cap and give it a quarter turn. You want to release the pressure slowly rather than all at once, which could send hot coolant spewing into the air.

Once the cap is safely off, slowly add coolant and water (if you have some) in a 50/50 mix until it reaches the fill line. Replace the cap and then turn on your car. If the car overheating lights go off and the temperature gauge goes down, you can drive to a service station, but be sure to keep an eye on that temperature gauge.

Know When to Call For a Tow

If you open your hood and your engine has puked coolant or oil everywhere, or if you look under the car and see a large coolant leak, it’s best to call for a tow. Additionally, if you noticed warped or cracked engine components or your engine oil is discolored (a milky sludge on your filler cap might indicate a blown head gasket), you will want to opt for a tow truck to take your vehicle to the nearest mechanic.

Car Still Overheating? Get the Problem Fixed.

Even if adding coolant when your car is overheating brings the temperature down, it likely won’t fix your initial problem. Your car may have a leak in the cooling system that will rear its head again a little further down the road. A leaky hose could eventually become a blown hose that keeps you from driving at all.

There’s also the possibility that it’s not your coolant system at all. You may have a faulty water pump, a crack in your radiator, problems with a belt, low oil, an incorrect air-to-fuel ratio, or a failing thermostat. Take your vehicle to a service station as soon as possible to have the problem diagnosed so a qualified mechanic can repair it and you can safely be on your way.

Frequently Asked Questions

What happens if you keep driving an overheated car?

Depending on the cause of the issue, if you keep driving an overheating car, you may cause irreversible engine damage. When driving your car with its engine at temperatures above its optimal operating range, you run the risk of issues like boiled fluids, melted sensors, broken hoses, warped cylinder heads, a blown head gasket, or a cracked engine block.

How can I temporarily fix my overheated car?

If you notice your car is overheating, turn off the A/C and turn on the heat. This will not fix the overheating issue, but it should help cool off the engine while you find a safe place to pull over.

Once you let your engine cool, you may be able to temporarily fix your overheated car by adding additional coolant. If you have a slow coolant leak or notice your coolant levels are low, this could cause the overheating issue.

For more serious issues, like a blown coolant hose or other major coolant leaks, you will not be able to fix the issue temporarily and should call for a tow truck.

Why is my car overheating when the coolant is full?

If your car is still overheating, even if your coolant reservoir is full, you may have an issue with another part of your engine. An engine may overheat if the coolant is not circulating fully through the system.

Other possible issues could be a faulty water pump, problems with a belt, low oil, an incorrect air-to-fuel ratio, a broken engine fan, or a failing thermostat. Take your car to your local mechanic for a diagnosis.

Will my car shut off if it overheats?

Generally, most cars will not turn off if the engine overheats. The computer system in some newer models may detect the rising engine temps and put the car in “limp mode,” which will effectively reduce the power output of your engine. You should still be able to drive, just slowly.

Why is my car overheating in traffic?

When you are sitting in traffic, especially on a hot day, your engine does not get the additional cooling benefit of airflow from driving. If you already have a small issue, like a slow coolant leak or a broken fan, sitting in traffic might cause your already warm engine to spike a temp.

About Kristen Arendt

Kristen is a writer and editor based in Colorado. She came to motorsports by way of her husband's passion for track days, autocross, and fast cars and is now the proud co-driver of two E36 325s and an overland-in-the-making Lexus GX470. She is a volunteer driving instructor with the BMW CCA Rocky Mountain Chapter and enjoys any event that involves getting behind the wheel or navigating from the passenger's seat.