I drained the coolant this weekend to change and refilled. The temperature guage now climbs into the red and I can hear gurgling noises like boiling after I pull back into my driveway and turn off the car. I live in the country and discovered by accident that pushing the throttle down all the way and accelerate hard for a few seconds, the temperature comes down very quickly but then starts climbing back up again.

My thought was that air is trapped and is preventing coolant from flowing thru the radiator. The bottom of the radiator says cool. I tried blowing into the overflow in an attempt to force water thru the system to force out any trapped air. This did not work but intrestingly when I do this I can hear bubbling coming from inside the passenger compartment, i'm assuming the heater core. That indicates that their must be some air space in the heater core that probably shouldn't be there.

Recommendations would be greatly appreciated