First off its a 95 sierra k1500 ext cab. short bed z71, when the truck is warming up the guage goes up to approximently 3/4 then drops back to just under halfway and goes back and fourth just over half ! if you shut the truck off for bout 5 mins the start it back up it reads 1/4 like its been off for long time but then repeats the process of going back up and coming back down ! I've changed the thermostat and cooliant still does this !
Any help would be appreaciated ! Thanks

 

have the same problem but mine just jumps up every once in awhile but if i put the heat on or speed up it goes back down so i said hell with it and just didnt mess with it

 

I believe you have a temperature sender that could be the problem. The sender is screwed into the block and sends a voltage to the gauge representing the temperature of the coolant. Other than the gauge itself, I don't know of anything else it could be. Good luck.

 

thanks ! Im prolly gunna change the sending unit and if that dont work maybe put a guage pod in !

 

Sometimes those senders goin bad can make the truck run like crap. But for sure I think it is ur sender. Easy fix!

 

thanks man ! I'll prolly change that this weekend !