i'm guessing that it's a leaking head gasket. That's what my mechanic told me today about my 1996 Ford Taurus.
Long before thinking the worst case (head gasket), start with replacing the thermostat.
If the engine coolant / anti-freeze hasn't been changed in a few years, it also should be flushed.The gauge does not cause the heat; it only shows what it is.
No - the gauge reports 'real-time' the engine temperature. If it is wrong, there is a problem with the sending unit on the engine. This is a pretty easy fix...
The fuel sending unit is sticking, or the wiring to the gauge is loose. These are the two most common causes of an erratic gauge.
No - they are in 2 totally different systems
Temperature.
StUck in open position
change in temperature causes change in pressure
The temperature sensor is probably bad
Its normally the sender. Take the wire off the sender (on the tank) and earth it. Turn the ignition on. If the guage rises the sender needs replacement. If not then its more likely to be a wiring fault than the gauge itself
A faulty temperature sensor, a wiring issue, or a blown fuse could cause a temperature gauge to stop working. It could also be due to a malfunction in the gauge itself.
bad temp sender usually. Bad gauge rarely.
Could be the coolant temperature sensor.