[Michael C Henry]

The thermostat may be involved. But if your current thermostat doesn't have a small hole in its't permitter you chould make a hole or change to a new thermostat that does . The thermostat is placed so that the hole is at the highest point. It will let air out while filling, and will let some coolant circulate past the thermostat during normal operation. A small hole is present in many of the new thermostats. The coolant flow the small hole will allow is not appreciable. Either you have some trapped air in your system or you slipped the thermostat. You could be reading the air tempreture, if you have trapped air. You want a solid flow of liquid and no air.