My understanding is that you only want to use the OEM oil filter in your 
Vanagon or risk oil pressure problems. So that is the VW dealer filter or the 
proper part number Mahl or Mann filter who are the OEM manufacturer. A lot, if not 
most after-market filters are the source of oil pressure problems according 
to many list postings over the years. 

I've never heard of a Bosch oil filter. I've used a lot of Bosch stuff of 
course, but never a filter. My concern would be that Bosch manufactures a generic 
filter with specifications that adapt to several different engines--say it 
might be for a Golf, Vanagon and Skoda. I'm guessing on which vehicles the oil 
filter part number you supplied might cover because on a google-powered parts 
search I could not find anything on that part number in English. In fact that 
search mostly came up with hits in a language with foreign characters and 
looked like this if Gerry's server will print the characters:

BOSCH 0 451 103 033 056 115 561 G, Фильтр масл.VW

You could have the above translated. But it's would be a lot easier to get 
the time tested and proven Mahl or Mann filter installed immediately. And fresh 
oil.

Something about the "mechanic" you mention in your e-mail doesn't sit right 
with me. I assume that's because somewhere in the subtext is the idea that you 
don't trust him either. Trust your instincts.

I'd change the oil and make sure I got the correct filter: Mahl or Mann

Best,
Jeff
83.5 Westy
LA,CA
In a message dated 2/5/2007 12:47:46 PM Pacific Standard Time, 
louizec@MYCINGULAR.BLACKBERRY.NET writes:
The oil filter used is a BOSCH. No 0 451 103 033; the  recommended filter for 
my 91. Is:; 070115561 

The bus seems to be running slightly hotter, even tho it is cooler outside. 
With fan coming on after being in traffic for 30 min or so and it is not hot 
outside.