on these engines the air is really hard to get out. if you fill it up with teh bleeder open 50% of the time you dont get all the air out of it. if the bleeder is broken off i *think* most of them screw into a bigger screw. if thast the case just loosen the screw the broken screw screws into (lol) and youll be fine. they sell a replacement but it replaces the bigger of the two screws and the screw you broke off. ANYWAY the best way to purge air out of the engine is to make sure its full and make sure the overflow is slightly, maybe 1/4" over the line, overfull. next start and run the engine till its at normal temp. after it gets to normal temp hold the idle at about 1500rpm until it starts getting warmer than it should. now this part is KIND OF tricky to picture but bear with me. when it starts getting warmer than it should rev the engine to about 2200 and let off. let the rpms drop down to 1200 and rev it back up to 2200 and repeat. you should be going 2200V1200^2200V1200^2200etc. this surges the coolant in the engine which also acts to push air past where it normally goes. now if the temp gauge starts dropping hooray. if it doesnt DO NOT let it overheat, shut it down. if you get it to drop, let it drop and warm back up and repeat the process a couple times making sure the overflow doesnt go dry. after you do it 2,3, or 4 times warm it up and shut it down and let it sit and DONT open the system. when it cools down itll suck up even more coolant from the overflow. refill overflow and see if it helps out any. if the process doesnt yield any results, have someone check the headgaskets. also, the lower intake gaskets are prime for leaking coolant. thats a good place to get air from. look on either side of your head. the easiest places to check are on the front head between the exhaust pipe and the intake on the driver side or behind the waterpump on the passenger side. look down the head, where the intake crosses from the head to the block on both sides. if you see quite a bit of coolant loss there it wouldnt be a bad idea to have those replaces. most of the time they just leak out onto the trans/engine. SOMETIMES they leak INTO the intake either into the valley or the cylinders if theyre let go long enough.