Vito 115 Emission Smell in Cab

[corvettetony]

Hi, I am the new owner of a Vito 115 CDI. I have had a problem with the O ring on the vaccuam pump which was leaking oil onto the exhaust manifold. I solved that problem and also changed the oil for Mobil 1, changed the oil, fuel and air filters. I hoped that was the end of the fumes in the cab but it wasn't, the smell is the smell you would get if you remove the oil filler cap and stick you nose in there. There are some dark smokey fumes visible upon removing the filler cap but they disappear as you raise the revs a little, I have removed the dipstick but don't seem to have any emissions from there. It seems to me that the cranckcase is not beathing properly . Can anybody advise me what the problem maybe or if I can do any tests. I am new to mercs and would greatly appreciate any help. The van has a full merc service histroy and has done just over 100,000 miles.

 

[meanie]

A couple of things spring to mind (although they are exhaust/combustion related)

Most common failing is the injector seat seal rings.
Is there an exhaust leak on the front flexi section under load?
Are the rear doors sealing properly?