After changing the oil and filter in my 1985 MB 300TD (172,000 miles) I cleaned the area immediately around the cap. Its usually caked with oil. The next day I noticed a slight amount of fresh oil leaked out from the cap.

The same thing is happening to my 1983 MB 300D (352,000 miles).

The oil caps don't look worn out and one looks brand new.

I use Delvac 1 and B100 but it appears the issue existed with the PO too.

Is this normal?

JJ