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Q: Engine overheat

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At McDonald's drive thru with a/c on, noticed it was blowing hot air. Looked at temp gauge and it was overheating. Pulled over shut truck off to cool down. Shut a/c off. Started truck with no a/c and it didn't overheat. Drove home and parked, turned a/c on and both fans operated and it didn't overheat again. I can not duplicate the overheat.

My car has 80000 miles.
My car has an automatic transmission.

A: The most likely cause of the issue that you...

The most likely cause of the issue that you experienced would be an intermittently faulty coolant temperature sensor. If the symptom has not come back and the cooling fans seem to be working, the sensor a very likely culprit. I would also check to make sure that your coolant level is within specification as well. If you come to find out that your sensor is not malfunctioning, it is also possible that you may have some air in your cooling system that could be causing the sensor to think that the vehicle is overheating when the air bubble passes by it.

To resolve that issue, have the overheating issue diagnosed firsthand by a certified technician, like one from YourMechanic. The cooling system may need to be bled of air.

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