I was under my new 2005 4.2td gu today and noticed what looks like a 12x12cm patch on the side of the sump next to the dump pipe. It looks like tar covered in a foil - at first I thought maybe it was to protect dump from the temperature of the dump pipe but maybe it's a bloody patch over a hole.

???!

Must say I've never noticed a 'patch' on the side of my 91.. But to be honest it's not the sorta thing you look for..

The tar and foil sounds sorta suss... It's is after all just a sump..

Yeah, maybe covering up. A rock hit.

Only one way to find out...

Mine has the same. 2005 model. I don't know what it is either.

Must be to protect sump oil from high dump pipe temp?

How hot would those temps be?? And it's not like it's constant..

They have it from 2002, not sure what it's for, but my series 3 & 4 had it.

For those wondering what its all about...