The place to start is by connecting a scanner to view live data and see exactly what the coolant temperature is. If it's normal, around 200 degrees, but the temperature gauge is reading too high, suspect the instrument cluster. The engineers at Ford have turned the really reliable cluster into another computer module, so now we have all kinds of computer-related problems we never used to see.
Your mechanic will also watch that coolant temperature to see if it suddenly jumps up too high. If it does, there could be a problem with the temperature sensor or its wiring, but those should both be down pretty far on the list of suspects.
If we were to assume the misfire and overheating are related, the leaking cylinder head gasket is a good suspect. Your mechanic will perform a test at the radiator with the engine warmed up and running. That involves drawing air from the radiator through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present, the liquid will turn bright yellow.
Saturday, April 4th, 2015 AT 8:29 PM