As I understand it, there is a relief valve in the Mahle and Mann
filters whose spring pressure is sufficient to  maintains the pressure
in the oil galleries of the WBX engine after shutdown. The spring
pressure in other brands, including Fram is insufficient to adequately
do this for the WBX engine, thus Fram and others, in combination with
improper oil viscosity (under most conditions 20W50 wt oil is
recommended - I run 15W50 Mobil One). contibutes to the infamous
"Vanagon Syndrome" .... a lifter going flat and clacking loudly for the
first 20 miles on startup after sitting for just a bit. It is an
annoying but not fatal racket, but for those not "in the know", it can
be a worrisome experience at best!!

Regards,

John Rodgers
88 GL Driver

Michael Snow wrote:

>> Are you using a cheap oil filter?  Use the OEM Mahle or Mann oil filter,
>> cheap ones can cause this because their anti-drainback valves don't seal
>> well and the oiling system loses its prime.
>
>
> I could be wrong here, and I'm sure someone will clarify, but I don't
> believe that the diesel filters have anti-drainback valves.  This only
> applies to the gas engines.  I would still use Fram only in an
> emergency.  Mahle, Mann, Knecht are the ones I trust.
>
> Michael Snow
> 1982 Westfalia diesel
>