Overheating Engines: What to Do Right Away

An overheating engine is one of the few car problems where minutes really matter. Keep driving and you can turn a modest cooling system repair into serious engine damage. Here's what to do the moment you notice the temperature climbing, and what to avoid.

Signs your engine is overheating

Watch for any of these:

• The temperature gauge moves toward the red or "H" zone
• A temperature warning light comes on
• Steam or smoke rises from under the hood
• A sweet, syrupy smell, which often means hot coolant is leaking
• The engine loses power or runs roughly
• A message on the dash telling you the engine is hot or to pull over

Some newer cars reduce engine power automatically to protect themselves when they overheat. If your car suddenly feels sluggish along with a warning, take it seriously.

What to do right away

Follow these steps in order:

1. Turn off the air conditioning. The AC adds load to the engine.
2. Turn the heater on full and the fan to high. It feels odd, but the heater core pulls some heat away from the engine. Open the windows if it gets too hot inside.
3. Find a safe place to pull over. Signal, move to the shoulder or a parking lot, and turn on your hazard lights.
4. Shut off the engine. Once you're safely stopped, turn the engine off to stop it from producing more heat.
5. Wait before opening the hood. Give it some time. Steam and hot coolant can cause serious burns.
6. Never open a hot radiator cap or coolant reservoir cap. The system is under pressure, and hot coolant can spray out.

What to check once it cools

After the engine has cooled for a good while, you can do a quick check:

• Coolant level. Look at the overflow reservoir. If it's empty or very low, that's a clue.
• Visible leaks. Look for wet spots or drips on hoses, the radiator and under the car.
• Belts. A broken or slipping belt can stop the water pump on some engines.
• Radiator fan. If you overheated in traffic but not on the highway, the cooling fan may not be working.

If the coolant is low and you have the right type of coolant or a premixed coolant with you, you can add it to the reservoir once the engine is cool. Water can work in an emergency to get you to a shop, but it's not a long-term fix.

Should you keep driving?

In most cases, no. Driving an overheating engine can warp the cylinder head, damage the head gasket, or cause even worse internal damage. If the gauge goes back to normal after topping off coolant and the shop is very close, some drivers carefully drive there while watching the gauge. If it climbs again, stop. When in doubt, call for a tow. Many service contracts and auto insurance policies include roadside assistance or towing, so check what you have.

Common causes of overheating

Overheating is a symptom, not a diagnosis. Common causes include:

• Low coolant from a leak
• A failing water pump
• A stuck thermostat
• A clogged or damaged radiator
• A broken cooling fan or fan relay
• A failing head gasket

A shop can pressure test the cooling system and run other checks to find the source. Our cooling system coverage page explains which of these parts service contracts often include.

Overheating and your warranty

Here's an important point. Many vehicle service contracts exclude damage caused by continuing to operate a vehicle after a warning sign appears. If a covered water pump fails, that repair may be covered. But if you keep driving after the gauge spikes and the engine is damaged, the administrator may treat the extra damage as preventable.

To protect your coverage:

• Stop driving as soon as it's safe
• Get a tow if the cause is unclear
• Contact the plan administrator before repairs start
• Keep records of coolant service and other maintenance

Our claims page walks through what the process usually looks like.

How to prevent overheating

• Check coolant level regularly when the engine is cold
• Follow the coolant replacement schedule in your owner's manual
• Have hoses and belts inspected during routine service
• Don't ignore small leaks or a gauge that runs warmer than usual

How Warranty Wizards can help

We help you compare plans from third-party providers and explain what each plan covers, including cooling system and engine parts. If you'd like to explore options, request a free quote.