Engine Overheating: Causes, Immediate Steps, and Repair Cost Guide
What to Do When Your Engine Overheats
If the temperature gauge enters the red zone or you see steam from under the hood: turn off the air conditioning immediately to reduce engine load. If the temperature does not drop within 30 seconds, pull over safely and turn the engine off. Do not open the radiator cap when hot — coolant is pressurized and can cause serious burns. Allow the engine to cool for at least 30 minutes before inspecting coolant level. Call a tow truck if coolant is visibly low or if the engine overheated significantly. Driving further with an overheated engine risks a blown head gasket ($800 to $2,500 repair) or warped cylinder head — both catastrophically expensive.
Common Causes and Repair Cost
Stuck-closed thermostat prevents coolant from circulating to the radiator — thermostat replacement costs $10 to $30 DIY, $150 to $300 shop. Coolant leak from hose, water pump, or radiator reduces coolant level below the threshold needed for effective cooling. Failed water pump no longer circulates coolant — replacement: $50 to $150 DIY, $300 to $700 shop. Clogged radiator restricts heat dissipation — flush: $40 to $80 DIY, $150 to $250 shop; replacement: $150 to $400 DIY, $400 to $900 shop. Blown head gasket (most serious) allows coolant to mix with oil or enter the combustion chamber — repair: $800 to $2,500 shop.