Loose head nut?

[whiskychaser]

Hey does this link work:

http://www.realoem.com/bmw/partgrp.d...82&hg=11&fg=15

Its the top diagram one of the nuts on there... Is that what you imagined?

Yep that link works fine. Its just what I thought. It occurs to me that if its a domed nut, you could be tightening it as far as it will go but it still wont be tightening down to the cover. Thats how the oil could be getting out. If thats the case a fibre washer should definitely sort it. Hope that helps