ive got a little issue i have a 97 hatch with a ls... its ran fine for, but recently my temp gauge moves up and down spurratically , itll go up and down up and down up and well you get the point and its moving to fast for the car to be getting that hot and then that cold again . i changed the thermostat and the coolant temprature sensor.. any suggestions ?

 

There are two temp sensors...did you replace the right one? One runs the temp guage, the other goes to the ECU.

 

i replaced the one on the thermostat housing