Posted by Peter Florance on April 08, 2002 at 21:55:10 from 65.120.51.194
The coolant air bleed screw (on thermostat cover) can sieze and booger if not protected with anti seize and updated to newer style hex head type. I watched the seller of my 'new' 528i break off the slotted bleed screw (only time I've been able to see in to the future; if only 5 seconds or so).
So tonight I pulled the T'stat cover off and started in on it. Heating with torch, BG Blast, vise grips etc. Nothing. Screw just got smaller and smaller.
So I sez to my self: "I need a better grip on this thing". So I drilled a hole in some 1/2" flat steel stock and mig welded it to the remains of the screw. Sure enough I was able to gently tap gently the steel back and forth until the screw loosened up and unscrewed from the cover.
Chased the threads with a 8mm tap and I'm back in business. Now I have access to a spare cover on a parts car head (1 hour away at Jeff C's) but I really wanted to see if it could be done. It can.