so i just bought a 92 p/u w/ the 22re (196k) and decide to drain the coolant since it looked kinna dirty and replaced the t-stat w/ a toyota one while i was at it, anyways all seems good except when i 1st start it after it's sat for a while and drive with the heater on then the gauge starts climbing, it doesn't over heat when it's at idle, only when im driving while the heater (heater is warm as normal) is on after the truck has sat for a while, so i figure i have an air pocket somewhere in the system, so far i have tried burping the damn thing several times already each time a different set up, 1st time i d/c one of the heater hoses that goes towards the h/c valve till coolant ran out, plugged it back up and toped off the radiator, 2nd time i tried letting it idle w/ the cap off for about 15mins, then the last time i parked the front a curb w/ the cap off engine running w/ a mix of idel and 1500 or so rpm revs to try and burp it, and so far nothing, same ol problem. So im hoping one of you guys might have had the same problem can help a fellow out here, thanks