Engine Overheating: What to Do Safely

01Safe steps, in order

If the gauge is in the red, a warning light comes on, or you see steam:

• Turn off the air conditioning and turn the heater on full. It pulls heat away from the engine.
• Pull over as soon as it is safe, out of traffic, and shut the engine off.
• Do not open the hood immediately if steam is escaping. Give it time.
• Never open the radiator cap or coolant reservoir on a hot engine. Pressurized coolant can cause serious burns.
• Wait until the engine is cool before checking anything, and call for help or a tow if you are unsure.
• Do not keep driving 'just a few more miles.' That is where most expensive damage happens.

02What it could be caused by

Overheating usually means the cooling system is either losing coolant or not moving heat away. Possible causes include a coolant leak from a hose, radiator or water pump, a thermostat stuck closed, a cooling fan not running, a clogged radiator, a failing water pump, or a head gasket issue in more serious cases.

A low coolant level is a symptom too, not just a cause. Topping it off without finding where it went usually means the same roadside stop again.

03Signs before it gets serious

Cooling problems often give notice weeks ahead:

• A sweet smell after driving, or white residue near hoses.
• Coolant spots on the driveway where you park.
• The gauge running higher than normal in traffic but fine on the highway.
• Heater blowing cool when the engine is warm.
• Coolant level dropping between services.

04Reducing the risk

Have hoses, belts, the radiator and coolant condition inspected as part of routine service, especially before summer heat and before a long trip. Cooling components age with time as much as with mileage, so a vehicle that sits still needs the same attention.