Ok...this might be lengthy...my temp gauge pegged out at 260 today...nothing changed no smoke or perkalating....thats spelled wrong...i shut the car off let it cool turned it on and the temp didnt change...water pump thermostat radiator have all been changed. the gauge dropped back to normal and didnt change untill i got home and parked it...where it proceeded to flutter up and down. i havent had a chance to look at the wires and sensors...but im afraid to drive it to work in the morning....anyone got some ideas advice or just straight up answers? 95 LT1

 

OK - a little confused - did you recently change thermostat/water pump/radiator and then overheating? Did the Gauge max out but the car never showed signs of overheating?

#1 - Check the level in the overflow & in the radiator - confirm it's not ACTUALLY losing coolant

The gauge is powered by a sensor in the front of the driver side head while the PCM from a sensor in the water Pump, and the dummy light actually has a 3rd sensor - which can simply be unplugged.

ShoeBox has a great page(s) on the cooling system:
ShoeBox Cooling - Operation & Testing

 

4th Gen LT1 F-body Tech Articles

I think this might be the link you were trying to post. Hope it helps !

 

Yup - Thanks

 

not to fix the problem but were problems causing more problems. all recent changes. ill look at shoebox. thank you very much i will be back with results.

 

To clarify -the "3rd sensor" mentioned above is for the coolant level/dash light, not related to the coolant temp gauge or the PCM input.