W203 2003 CDi 122 hp (90 kw) - 330.000 km

What could cause some kind of residue on the left side of the intercooler (the side which gets the pipe from the turbine) and why I have oil/residue on this thing which I don't know what it is...

https://i.imgur.com/7Ir5u4N.jpg - residue

https://i.imgur.com/pfcyC0j.jpg - the 'thing'

I was thinking about some seals..but don't know where and what..

Any help appreciated.