Most likely a bad sensor/relay
bad temp sender usually. Bad gauge rarely.
We replaced the temperature gauge in my 1991 Chevy blazer what is the normal operating temp?
Hey Mischelle==It is great sat this temp. If you want you can have a manual gauge installed temp to see if the electrical gauge is correct. The vibration is the rotors or possible the rear drums. Either one can be turned to get rid of it. GoodluckJoe
Temperature Fluctuation simply
A bad sending unit in the gas tank.
220.
on the side of the radiator
1990 Chevrolet Lumina temperature sender is located on the back side of the thermostat housing. The sender has a wire that goes to the temperature gauge.
StUck in open position
change in temperature causes change in pressure
Temperature.
Bad temperature sending unit? Bad gauge?