Temperature warning light
The buyer question: "temperature warning light"
Treat an overheating warning as an immediate stop condition. Safely pull over, turn off the engine when the manual directs, and do not open a hot cooling-system cap.
What could cause it
More than one problem can cause the same symptom. These are places to inspect, not a diagnosis.
- Low coolant or a cooling-system leak
- A radiator fan, thermostat, water pump, or belt issue
- A blocked radiator or hose problem
- A sensor or vehicle-specific cooling-system fault
Safe things to check
Keep clear of moving parts, hot components, and traffic. Use the owner's manual for vehicle-specific instructions.
- Watch for steam, a rising gauge, warning chimes, or a coolant odor
- After the vehicle is fully cool, check the reservoir only as described in the manual
- Do not put hands near a fan or open a pressurized cap while hot
Stop driving if the temperature warning stays on, the gauge is in the hot zone, steam appears, or coolant is leaking. Let the vehicle cool away from traffic and arrange professional help.
What a mechanic may check
A technician may pressure-test the cooling system, inspect hoses, fans, thermostat, pump, belt, radiator, coolant level, and engine temperature data.
If you are considering this car
An overheating event is not a minor listing detail. Ask for the cause, pressure-test results, repair records, and an independent inspection. A fresh coolant fill is not enough.
Questions for the seller
- When did the temperature warning appear, and did the car lose coolant?
- Was the engine ever driven while hot or shut down because of overheating?
- Can I see the cooling-system test and repair invoice?