The thermostat housing is at the end of the upper radiator hose correct? Trucks been runnin hot but when I turn the heater on it goes back to where it should be my guess it's the thermostat. Any suggestions or comments

 

You can always replace your thermostat. Those things don't cost much and it's an easy job.

Could be wrong, but I can't think of any other causes from the top of my head. perhaps someone else knows more and can chime in

 

Sounds like it's maybe just low on coolant, have you checked?

 

I would check the fan clutch. If the thermostat was stuck shut turning on the heater wouldn't keep it from overheating.

 

Ya the coolant is full. I just got the thermostat this morning gonna replace it this afternoon

 

Come back and let us know if it fixes your problem.

 

This.

 

Well the clutch fan ain't electrical all manual so I doubt it's the fan gonna work on the thermostat on lunch break and get back to yall

 

It's a thermal fan clutch. Yes they go bad.

 

I put it in And there is a small air bubble i dont know why but the gasket and permatex is on correctly and the bolts are torqued down