An overheated engine is one of the most serious issues that can occur in a vehicle. When engine temperatures rise too high, severe internal damage can quickly result. Being prepared and taking the proper steps when your car does overheat can literally save your engine.
This comprehensive guide outlines what you need to know when dealing with an overheating car – what actions to take, what mistakes to avoid, and how to prevent overheating problems in the future. Whether you’re a seasoned driver or just got your first set of wheels, these tips can help ensure you respond correctly in this critical situation.
Recognizing the Signs of an Overheating Engine
Before any damage occurs, it’s important to recognize the early warning signs that your car’s engine is running hot:
- The temperature gauge creeps up to or into the red zone
- The “coolant hot” or “check engine” warning light activates on the dash
- You hear hissing or bubbling noises from under the hood
- Steam or leaking coolant becomes visible from beneath the hood
- The heater starts blowing hot air even when the temperature is set to cold
Any of these indicators mean it’s time to take action. The most serious symptom is steam blowing out from under the hood – this means cooling fluid is boiling over and your engine is at serious risk. Don’t ignore the warning signs or try to “get home” before dealing with it – a severely overheated motor can fail in minutes.
What To Do When You Get an Overheat Warning
When you see any sign of the engine overheating, here are the steps to take right away:
Pull Over and Stop – Get the car safely off the road and switch off the engine immediately. This stops it generating more heat and gives it a chance to start cooling down.
Pop the Hood but Don’t Open it – The hood will be very hot and opening it could release scalding steam and spray. Wait until any hissing stops and steam dissipates before actually opening the hood.
Let It Cool – Do not attempt to restart or open the radiator cap until the engine is fully cooled. This takes at least 30 minutes and longer is better. A cooling engine makes ticking and creaking sounds – when you don’t hear these noises anymore it’s ready.
Check Coolant Level – Once fully cooled, open the radiator cap cautiously and check the fluid level. Low coolant is the most common cause of overheating. Top it up carefully if needed, but don’t remove the cap until cool.
Look for Obvious Leaks – Scan hoses, radiator seams, water pump and other components for leaking fluid. Top up if there is significant loss. Also check that cooling fans run when started.
Check/Clear Radiator Screen – Ensure the radiator screen isn’t obstructed with debris. Carefully clean out any dirt, bugs or leaves blocking air flow.
Turn Heat On Full Blast – Run the heater at maximum heat setting. This draws engine heat off into the cabin as you drive, cooling the engine.
Once cooled and leaks addressed, you can start driving again – gently and for limited distances only until the cooling system is fully checked and repaired.
What Not To Do When Your Car Overheats
When faced with an overheating vehicle, it’s just as important to know what NOT to do as the proper steps:
Don’t Keep Driving – Continuing to drive with the temperature in the red zone will almost certainly escalate damage and could ruin the engine.
Don’t Remove Cap When Hot – Taking the radiator cap off while still overheated can allow dangerous spray of superheated fluid under pressure.
Don’t Add Cold Water – Adding straight cold water to an overheated engine can crack components due to rapid contraction.
Don’t Rev the Engine – High RPMs generate more heat. Keep RPMs low and gentle acceleration if you must drive it prior to repair.
Don’t Turn the Heater Off – Blasting the heat helps dissipate engine heat. Turning it off will cause further overheating.
Making any of these mistakes when your engine is overheated can allow a bad situation to become catastrophic. Knowing what not to do prevents causing further damage.
Preventing Cars From Overheating
Prevention is the best medicine when it comes to overheating. Regular maintenance and checks can identify issues before they strand you on the side of the road:
- Check fluid levels frequently – Low coolant/antifreeze is the leading cause of overheating. Top it up if low.
- Change coolant on schedule – Flushing and replacing it per manufacturer spec (usually every 2-5 years) keeps the cooling system in good order.
- Replace bad hoses – Cracked, swollen or leaking hoses should be replaced. Check clamps are tight.
- Check water pump and belts – Replace if worn water pump bearings are detected or drive belts look cracked.
- Clean radiator screen and fins – Remove debris like leaves that can block air flow and cause poor cooling.
- Fix oil leaks quickly – Oil leaks can foul radiator fins and tube passages.
- Check fans are working – Engine and radiator fans must activate to cool when AC is on. Replace faulty fans promptly.
With vigilant maintenance and good cooling system condition, most overheating events can be avoided altogether.
What To Do After An Overheat Event
Once you’ve limped the car safely to a stop after an overheat situation, it needs to be thoroughly evaluated before you can reliably drive it again. Here are the steps needed:
- Allow full cool down – Let it cool completely before you open the cap or start the engine again.
- Pressure test – Have the cooling system tested at a shop to ensure no engine-warping leaks developed. Address any issues.
- Flush radiator and hoses – Overheating may leave contaminants that can re-clog systems. A flush helps get it clean.
- Replace coolant – Old coolant that has overheated loses effectiveness. Always put in fresh after a major overheat.
- Check water pump – Have the pump tested, as overheating failure can damage its impeller.
- Check fans and thermostat – Make sure cooling fans engage properly and the thermostat opens to circulate coolant when hot.
- Consider a combustion leak test – Severe overheating can warp cylinder heads allowing coolant to leak into cylinders.
- Check for engine damage – If it overheated badly or multiple times, internal engine components may need repair.
It takes thorough inspection and repairs following an overheating episode to get a car ready for reliable operation again. Don’t limp it around chronically overheating or you’ll likely inflict terminal damage.
FAQ’s on Overheating Car Engines
What temperature is considered overheating?
Once the gauge reaches the red zone (usually around 235-245°F), it’s overheating and steps need to be taken immediately.
Is it safe to drive when my engine is running hot?
No – driving when in the red zone can quickly escalate overheating damage. Safely pull over and shut off the engine immediately.
What is the most common cause of cars overheating?
Low coolant level is the number one reason. Internal or external coolant leaks, faulty water pump, bad thermostat, and blocked radiator fins are other common causes.
Can I use water if I don’t have coolant?
Plain water can be used temporarily in an emergency, but replace it with proper coolant/antifreeze mix as soon as possible.
Is it okay to remove the radiator cap when the engine is hot?
Never remove the cap until fully cooled. Hot fluid under pressure can spray out violently when the cap is taken off prematurely.
Can overheating damage be covered by warranty?
If due to a defective component still under warranty then coverage is possible. But overheating due to lack of maintenance is generally not covered.
How often should I check my coolant levels?
Check levels at least monthly when performing routine engine checks. Top up with the specified coolant mixture anytime it’s low.
Now you know exactly step-by-step what to do, what not to do, and how to prevent overheating problems when they strike your vehicle. Stay alert for early warning signs, react promptly and properly, and avoid the mistakes that can turn a minor overheat into major mechanical disaster. With this handy guide, you’ll smoothly handle this common driving dilemma. Safe travels!