Audi 2.5 five cylinder turbo diesel engine it's the only one i've ever seen and i've brought this question up on other forums only to be met by blank answers, or simply that won't work. Now audi have done it like this on thier engine and i'm assuimg they've had no problems cos i know of a few 2.5's on over 140k miles with no trouble.

That said this is the old A6 engine which stopped being made in 1997? and the same engine in the transporter doesn't use this method and nor does any other audi asfaik in the current range.

The clever thing is though it uses a banjo bolt as a sump bung, attached to the banjo is the oil return, obviously doing it like this would save alot of trouble when converting a n/a engine to turbo. Prehaps audi stopped doing this cos people kept overtighting the banjo bolt maybe?