Q: Why is my temperature gauge going up and down?

Hi There, It sounds like you may have a sticky thermostat or potentially a cooling fan that may be working intermittently. The thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature.

The cooling fans may be working intermittently as a result of a faulty cooling fan relay or resistor. The difference between the relay and the resistor is that the relay controls the power to the fan in total, meaning that if it is not working properly, you may have a faun that comes on randomly, stays on all the time or never comes on at all. The resistor controls the stages at which the fans come on. In either case, this can cause an erratic fluctuation in the fans ability to help cool the radiator. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.