I’m stumped, replaced 2 thermostats and each time it seems the problem resolves for a bit. I recently replaced the thermostat with the OEM and followed the burping guidelines. Car drives well and doesn’t overheat. I double checked it again today after doing a couple of WOT runs and I can see water dripping from the cap as if pressures are high inside the tank. Temp is normal, heater blows hot air. I’m stumped. I did a leak down test recently and no signs of a blow head gasket. I watched the car cool down and heard air escaping from the cap as if was burping and the water level dropped there after. No idea what to do at this point.