What To Do When Your Vehicle Overheats and How to Diagnose an Overheating Engine

Jun 12, 2024

Welcome back to our Gearhead Guru Guide series, where we help you be the best automotive enthusiast you can be! Today, we’re covering the basics on what to do when your engine overheats, and how to diagnose an overheating engine, plus how to prevent it in the first place. You’ll also learn to use your sense of touch, sound, sight, and smell to be aware of warning signs, and what to do if the unavoidable overheat emergency happens. Let’s get started!

What are the signs that your vehicle is overheating?

Aside from the obvious temperature gauge spikes or car shutting off, there are some precursor signs that you should not ignore when it comes to alerts the engine is overheating. You’ll be able to assess by look, touch, smell, and sound very quickly thanks to these tips!

Touch.

You may notice that the hood is extremely hot, and you’re unable to leave your hand touching the hood for more than a few seconds. Excessive heat means there is something seriously wrong, and you should call your local service center for a tow and repair appointment.

Visuals.

If you notice any wisps of smoke or billowing steam from under the hood, it’s a surefire sign the engine has overheated. This is due to the fact that the coolant has hit its boiling point, which creates pressure in the cooling system. You may also notice the temperature gauge is climbing up into the red or “H” portion of the gauge. Another sign could be puddling or pooling of coolant which may look like a green or blue-green, orange or yellow, or a pink hued liquid depending on the fluid used for your vehicle and driving conditions. You may also notice the check engine light also turn on or blink.

Smells.

A burning and overheating engine has a distinct smell of burning rubber/plastic, burning oil or sulfur-like aroma, or a strange ozone “heat” type smell. If you smell a sticky-sweet, maple smell it may be the leaking coolant under the vehicle.

Sounds.

You may hear some thumping or ticking noises, which indicate an engine system failure, and that it’s about to overheat. If you notice any hissing sounds, it can indicate that the coolant has reached its boiling point; this may be either steam escaping the hot engine or perhaps coolant leaking onto the hot engine components, and either option is a serious issue.

What should you do if your car is overheating?

Immediately pull over your vehicle to the first safe space or opportunity you have, but until you can, you should roll down your windows and crank up the heating system. This process will help draw heat out of the engine area and away, but it will heat the interior pretty quickly, so pull over ASAP especially if it’s hot outside!

Once you’ve pulled over, turn off the vehicle, but DO NOT touch or open the hood of your car until you’ve let it rest for at least 30 minutes. If you happen to find a safe space out of the sun, that may provide additional help to cool off the vehicle. Keep your eye on the temperature gauge to alert you when it has reached a cool temperature in the normal range. Call a tow truck to bring your car to the nearest garage.

If you are unable to acquire a tow and driving is the only option, place your hazards on and carefully restart the engine once it’s fully cooled, and head to the nearest repair shop. If you’re driving to a mechanic, it’s IMPERATIVE that you keep the heat blasting and have your eye on the temperature gauge; pull over and let the vehicle cool until normal range and then continue your drive, but DO NOT drive it on the H or red-alert overheat warnings.

If the engine has completely overheated to the point the vehicle has shut off while you were driving, we recommend letting it cool, and then only turning it on insomuch as to pull over safely and requesting a tow rather than driving it in as that may cause further damage.

Can you repair an overheated engine?

Yes, and no. An overheated engine will not resolve on its own and requires a professional mechanic and service technician’s help. An overheating engine can cause significant damage to the vehicle and multiple components including the cylinder heads, head gasket, hoses and belts, and the engine block itself. This may require individual parts to be replaced and it will run again, but it will not be the same and is prone to further damage issues down the line. Additionally,in severe cases, an engine that has completely overheated and seized may need to be replaced entirely. Either way you slice it, they’re costly repairs, so it’s best if you’re able to start a car maintenance and repair nest-egg of savings to be better prepared for emergencies such as this.

How can I prevent my car from overheating in the first place?

Keeping up with regular maintenance appointments, especially oil changes and radiator/coolant exchanges and flushes are a vital part of engine maintenance. You should also be performing weekly checks on your engine oil, as well as monthly checks on your coolant levels. Additionally parking in the shade will help your car stay cooler while not in use, and help it cool down faster after driving. You should also maintain your Heat/AC system with seasonal service checks. Remember to regularly top off your fluids, and never drive your vehicle with any warning lights on unless it’s right to the service center! Consider opting for a roadside assistance plan either as part of your vehicle insurance package or an independent plan such as AAA, which will greatly help you during emergencies with towing assistance and traveling service technicians.