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Q: Overheating.

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I was driving my car with heather on and it started to overhead so i turned off my heather and it was fine but at times as i park or drive a fan sound comes on. What is the issue? Thanks

My car has 90000 miles.
My car has an automatic transmission.

Hi There, It sounds like you may have a faulty coolant fan switch that may be working intermittently and at the wrong times causing your motor to overheat. As you may know, the coolant fan relay helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this relay is not working properly, this can cause the fans to come on intermittently, stay on all the time or sometimes not at all. When this happens you will notice a temperature spike and drop occasionally as the fan comes on and off. This may also explain why the cooling fans remain on after the motor is off.

You may also have a faulty thermostat that is not working properly causing coolant not to flow properly to and from the motor at the proper temperature thresholds which may also cause spikes in the temperature readings. The thermostat opens and closes at specific temperatures to allow coolant to flow to and from the motor circulating back through the radiator which is cooled by the fans. When the thermostat is not opening and closing at the correct times, this will also cause the engine to overheat. I would suggest having an expert from Your Mechanic come to diagnose and inspect your cooling system.

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