Low Coolant? Weak Temerature sensor? Weak gauge Gauge working properly and recording the thermostat opening and closing as engine temperature fluctuates
Thes sending unit is located inside gas tank.
When you turn a corner the guage fluctuates.
Your pressure gauge may be broken....If it fluctuates, then you know its not your gauge, but if your gauge always reads 80, it may need to be replaced.
on the side of the radiator
because your thermostat is opening and closing as the engine temp. fluctuates
The temperature gauge on a car fluctuates because the car's thermostat is opening and closing. The gauge goes up when the thermostat closes and the gauge goes down when the thermostat opens.
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.
Could be low on coolant or a faulty thermostat.
Because it is a Pontiac. Sorry, man.
your float could be stuck