temp guage on dash is or was maxed out..

[Oopsgreg96]

started up this morning everything ok, went to my dads half hour away, fine. Left four hours later, when I started truck at dads, and temp guage was over in the max area, then drove a little farther and it started to come down some, then back up, all in one mile. Got back to my house and overflow tank ok and up to mark, and not exsessively hot either. Grabbed top hose and squeezed liquid pushed back into over-tank. Could this be my dash guage or sending unit?
Not to sure so far, Thanks, Greg

[CleviteKid]

What year truck? Any modifications?

If the coolant level gets low, you can get hot spots in the heads, steam and air, and get erratic readings, and the burping sends coolant to the overflow tank, so you think everything is cool.

I would recomment running the engine at idle, with the radiator cap off, and keep adding 50/50 coolant and water as the engine seeks to purge itself of the air.

Let us know about this, and then we can think about the sender and the gage.

Dr. Lee :cool: