I just bought a 1990 525i with an M20 engine. This weekend, I changed the coolant. The bleed screw was a little hard to break loose, but it came loose with a little bit of force and I thought things were fine. I filled the radiator and replaced the bleed screw. I was unable to completely tighten the screw down. The threads on the bleed screw looked like a portion were wiped out, so I replaced it with a new factory screw. I am still unable to tighten the bleed screw enough to keep coolant from flowing out once the car warms up. It appears that the threads are shot on the female side, ie the radiator.
This is the original radiator and I did not cross-thread the screw!
Is there a repair kit for the radiator threads or does someone have an idea to fix this so I don't have to get a new radiator?