Hi having an issue 1995 gt 5.0 5 speed. When i start the car my temp gauge goes way past hot as far as it can go. Then sometimes after driving awhile it pops back to normal. Was first told that it wasnt an issue. Now it is idling super rough/low and dying. The thermostat, coolant temp and IAC sensors have all been replaced. Being suggested that the whole gauge cluster needs replaced. Anything else to look at?