well, there is a certain procedure to bleed the air out of many e34's. The key here is a bleed screw...It should be located right next to the radiator cap.
Procedure: remove radiator cap and unscrew pressure bleed screw right next to it. (the screws under the car should be closed by now.
fill the tank with 50/50 (BMW coolant/Distilled Water) until you see bubbles come out of the pressure bleed screw. Continue this until there are no more bubbles. The whole process will get a little messy with the coolant coming out of the pressure bleed screw...but then again, the key is gettin all the air out while you refill the system. oh and the car should be off while you fill...
for more help, go to
http://www.bmwe34.net/e34main/maintenance/...replacement.htm or e-mail me
llzoom_zoomll@hotmail.com (those are L's btw)
good luck