The radiator of my 2002 M5 had a leak from the housing of the radiator. So i replaced it, but I still have the leaking problem coming from the drain plug of the new radiator. I have changed the drain plug O-ring and even put plumbers tape around it hoping that would seal it enough to stop the leak. I also used a different drain plug with a new O-ring, the old O-ring and plumbers tape. Nothing seems to stop the leak. The radiator had a few scuff marks on the fans but it didn't seem to puncture any of the lines.
I also checked the hoses and there are no leaks coming from the hoses or the seals of the hoses. There is nothing plausible to me to do other than replace the new radiator with another new one.
Any solutions, tips would be helpful so I don't have to spend tons more money!!!