New T*Stat and Overheating episode

[amenges]

I recently installed the JET 180 T Stat. I installed in with needle valve up, just like oem. After installation i warmed up truck to make sure there are no leaks and everything was ok. After driving yesterday I first noticed something. The thermostat gauge goes all the way to the middle (where it normally was with the oem t stat) and then cools down to the normal spot (about the first 1/4 of the gauge)

Well I figured that was normal so didn't pay any attention to it. Then after driving around 30 miles and sitting at a red light my check gauges alarm was dinging. I look down to see my thermostat almost buried on the hot side. I panic, pull over and put it in park, and then gauge quickly goes back down to the first 1/4 again.

Anyone had this problem? Could it be caused by the needle in the thermostat "sticking"?

 

[KGBIGCOUNTRY]

Did you burp it? Sounds like you have an air pocket.

 

[amenges]

I believe so. I installed the T-Stat, filled the radiator back up through the cap. let it warm up to temperature.. let it cool down, and filled it up again. The reservoir is full and under the radiator cap is full

 

[SmokedRam]

The best way to burp it is to park the truck so the front of the truck is higher than the rear...open the cap, let the engine run so the tstat opens. Sometimes it takes 2 or 3 times to get all the air out.

 

[amenges]

After refilling it 5 times I haven't had any issues since. Thanks Guys