Im kinda nervous, Ive been having my heat come and go for a bit now and i also noticed that my temperature gauge is up and down a lot also. Driving, idling...doesnt matter. The truck used to run at just about middle, on the temp gauge. When the heat is off and im driving i have no problems. But when it is on and im driving or its on while idling is when i have the issues. Ive replaced the thermostat, and i still have the same problems. the truck just turned 202,000 miles and it looks like brand new. i love the truck. . . a friend at a local dealership told me it could be the head gasket? Never herd of such a thing, Hoping you guys can help me?! Thanks! And i am new to this whole forum thing, any pointers would help haha

 

4.7? Tons of threads on head gaskets. If you just did the t stat. Could be an air pocket.

 

Its a 5.7 hemi.

 

Sounds like an air pocket. Try burping again.