When you drove it, was it in stop and go traffic only? If so, did the cooling fan turn on when it got hot?
As far as air pockets, many times when you drain the cooling system and refill it, the coolant doesn't get all the way through the system and leaves air pockets. This can cause it to heat up. Is the heater working properly? Usually, the heat won't work properly if there is air in the system.
Since the gauge is going up and down, it leads me to believe either the coolant is low or there is air in the system.
Let me know.
Monday, February 2nd, 2015 AT 6:40 PM