air bubbles in overflow?

[slider_buck]

it all started the other day when i was going to work and the thing quit putting out hot air from the heater and got hot. when i seen the gage going up to about 260 i pushed in the clutch and killed her and coasted it up the road to a pull-off. i though for sure i had a blown head gasket because of air bubbles getting in to the overflow bottle so i tore it down and sure enough #6 and #7 blew. well i got it all back togther and still have the same problem. i have a new 3 core radiator, new 180 stat, new hoses, new water pump. what else could it be. the funny thing is that if i set there and keep it reved up to about 3 grand it will stay cool but when i let it idle it will start to heat up. then every now and right about when the stat should open up the temp gage will climb up really quick and the coolant will start to rush out the radiator, it will blow about half the coolant out when it does this. i did both a leak down and compression test which were ok. i'm stumped.

[429mustang]

Did you get all the air out of the system? My car was a mess trying to get it out, it blew out a gallon or two as I kept adding it until it finally stopped.

[slider_buck]

well it ended up being 2 things. one my stat was in backwards and 2 the fan clutch wasn't engaging. for now i drilled two holes in the fan clutch and put 2 screws in it, works great for now. going to autozone in the morning to either buy another clutch unit or get a flex fan. already have one flex fan i didn't use from another vehicle, probably going to trade it in on one for the mustang.