Cooling System Help

[rebscoach]

I recently replaced my t-stat in 99 v-6 4.0 ohv ,now I can hear thumping sounds coming from the heater core area. No other problems temp is fine and heater works great . Could this be trapped air and how can I fix this.

 

[ExplorerDMB]

I don't believe explorers have bleed off screws for the cooling system, but I would try taking off the radiator cap and squeezing the lower radiator hose to see if any air comes out. How did you install the thermostat - just disconnected the hose and removed the housing? Or did you drain the system, took the radiator cap off, then the hose and the housing?

-Drew

 

[rebscoach]

Cooling System

Thanks Drew for responding I drained small amount out of radiator then removed T-stat housing and replaced T-stat and made sure it was positioned right then refilled radiator checked for leaks and had this problem ever since.

 

[MONMIX]

yeah sounds to me like it needs to burp. Heat it up, let it cool. Top it off. Repeat two more times.

Long story short. Air in the system.