Distributor rattle and oil leak

[Eyvind Spangen]

The distributor on my car rattles at about 2000 rpms, not loud at all,
but I can hear it. That's no big problem, but the inside of the
distributor is oily.. Not much, but enough to be noticeable. I guess
this won't do any good neither for the performance or reliability.. 

What causes this? Do I need a new distributor?

-- 
E. Spangen
'90 Audi 200TQ 20v