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Q: Over heating

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While my son was driving the truck yesterday, it over heated. I changed the thermostat and sensor this morning. I drove around neighborhood for about 20 min and it seemed fine. But as soon as I hit 40mph the gauge went into the red, and my check engine light came on, and it ran really rough. Could it be my radiator?

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

A: This can be caused by a number of things su...

This can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, 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. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.

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