Date: Sun, 25 Mar 2012 09:56:51 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Oil Filter
In-Reply-To: <093501cd0969$8af46160$a0dd2420$@com>
Content-Type: text/plain; charset="iso-8859-1"
Technical responses from the public relations or support people of some
companies should not always be taken as the truth and something posted on
the list or in the archives doesn’t make miss-information any more of a
fact.
Almost all VW engines that have oil filters have some type of bypass in
case of filter blockage. Even the type 1 engines that only had the inlet
screen. The screen was designed that if It became blocked with even ice (yes
frozen condensate in the air cooled engine oil) the screen could be sucked
down so oil could flow past it. The type 1 oil pressure relief was even
designed to bypass the cooler in times of high oil pressure to let it warm
up faster and get the pressure down. That can be a whole other topic.
Anyway, the Waterboxer engine does not have any filter or cooler bypass
capability, only pressure relief. So since the Mann and Mahle filters for
the rest of the VW did not have a bypass a different filter had to be
specified that included this option. No for most other filter manufacturers,
do to multi-vehicle support and the immediate liabilities of have a filter
blockage damage an engine a bypass valve is there. They operate at different
pressure differentials and there are other factors as part of filter design
but that is why the aftermarket can specify the same filters for the Vanagon
and other VWs where the OEM has different filters specified. I doubt there
is any difference in the filter material or anti drain back. And since the
filter isn’t mounted upside down the anti-drain back is not an issue is not
the cause of VW noisy lifter syndrome. If it was we would have nosy lifters
after every oil-filter change.
Now let's talk filter quality and strength. Back in the early days of
VW/Audi inline engines oil filter failures were a common problem. Without
hydraulic lifters and the closer tolerances of these engines and the need
for a lot of lubrication for the camshafts lack of bearings these engines
operated at high oil pressures. 90psi on a warm engine was the normal. The
Mann-Mahle filters were designed for this. I saw many aftermarket oil
filters, cans bulging or even a few were the can blew off the base. As
hydraulic lifters came about the oil pressure had to be reduced otherwise
all the valves could float open especially on cold engines.
The Waterboxer should never see pressures high enough to damage any filter.
Lately I have been satisfied with the Fram tough Guard and Mobil 1 filters
and past oil analysis has shown them to be effective even for extended drain
intervals. Since this topic has come up I have done some research and I am
going to try the Wix/Napa.
Dennis
You're right. Some years ago a list member actually emailed Mahle themselves
regarding the filter differences. Mahle replied that the Vanagon filter has
a better anti-drainback valve than the Golf filter, because that the Vanagon
engine is more prone to oil starvation at startup. They also stated that the
Vanagon-specific filter has a higher quality filter material than the Golf
filter. It's in the archives.
- Ron Salmon
The Bus Depot, Inc.
www.busdepot.com
(215) 234-VWVW
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Toll-Free for Orders by PART # : 1-866-BUS-DEPOT
