When My truck is Idle i will start to "over heat" with the temp gauge reaching 210 or higher if I don't move, but once I start to drive the temperature will drop pretty drastically from 210+ down to about halfway between the 210 and the start of the temp gauge. So I assumed I had trapped air in the cooling system causing hot spots. Could this just be my radiator not dissipating the heat? Maybe I do need to just add more coolant. I will give it a try. So Really you haven't ever had to purge the air out of the sealed cooling system. This definitely is starting to seem like user error. Sorry this is my first Jeep ever and I don't know much about vehicles but this Truck is definitely teaching me some things.