Why Does My Car Overheat When Idling But Not When Driving?

How do I know if my coolant is circulating?

Look through the radiator filler neck to see if the coolant flows.

At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open.

If you find the coolant is flowing, it means the thermostat valve is open..

Why does my car overheat when sitting still?

If your car begins to overheat when idling, but the temperature gauge moves back down once you get going, it’s most likely due to a broken radiator fan. … However, when your car is sitting still, the radiator fan should kick in, keeping the air moving over the radiator to help cool down the coolant.

Why does my temperature gauge go up when idling?

The rise in temperature is due to the fan clutch not engaging the fan clutch until the temperature gets too high. This is the first indication that the cooling fan clutch is going bad. If you replace the cooling fan clutch using the correct one for your vehicle, it should fix the temperature problem.

How long can a car idle without overheating?

All cars should be made to be able to idle indefinitely without overheating. Basically after so many minutes the car with adequate cooling should have reached a stable thermal equilibrium and if that’s so then it should idle for an hour, two hours, 8 hours, 12 hours, a day with no further issues.

What are the signs of a bad thermostat?

Symptoms of a Bad or Failing ThermostatTemperature gauge reading very high and engine overheating. The first and potentially most alarming symptom will be the temperature gauge reading high into the red within the first 15 minutes of your vehicle engine running. … Temperature changing erratically. … Coolant leaks around the thermostat housing or under the vehicle.

How do you know if your Headgasket is blown?

How to Tell If You Have a Blown Head GasketExternal leaks of coolant from under the exhaust gasket.Overheating under the hood.Smoke blowing from the exhaust with a white-ish tint.Depleted coolant levels with no trace of leakage.Bubble formations in the radiator and overflow compartment.Milky discoloration of the oil.

What would cause a car to overheat when idling but not driving?

The most likely reason for this type of problem is that your fan isn’t working, but the reason, and the fix, will differ depending on the car you drive. Intermittent overheating problems can also be caused by low coolant, air in the cooling system, a bad coolant temperature sensor, or even a faulty gauge.

How do I know if my thermostat or water pump is bad?

Symptoms of a Bad or Failing Water PumpCoolant leak at the front-center of your car. … Water pump pulley is loose and making whining sounds. … Engine is overheating. … Steam coming from your radiator.

How do you know if your thermostat is stuck open?

Symptoms of a bad thermostat Thermostat stuck open: When the thermostat is stuck open, the engine temperature drops below normal when driving, especially on the highway in cold weather. A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too.