Date:         Fri, 2 Feb 1996 00:06:24 -0500
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         DHaynes57@aol.com
Subject:      Re: wasserboxer oil buzzer warning = Fram

In a message dated 96-01-31 13:56:29 EST,
fairwind@northernnet.com (Dan Houg) writes:

>Okay.  Here I go on another tirade against Fram.....
>
>This just happened today.  Actually, the last several days.  On my 
>last oil change 300 mi. ago, i used a Fram filter because i didn't 
>have a VW one on hand.  Still have that stock-pile from when Frams go 
>on sale for $1.99 :)      Anyway, the oil light and buzzer had 
>started going off at specifically 2200 RPM.  above that or below that 
>RPM it behaved.  actually, it seemed to go off most when the rpm was 
>up around 3000 or higher and then hit 2200 on the downsweep.  Picked 
>up 6 Autobahn filters at the dealer for $7.50 ea.  put one on and the 
>problem is cured.  period.  same oil. same conditions except for the 
>filter.  i'll blame the Fram, thank you.
>
>Now, i use Frams exclusively on my Toyota and there's not a wit of 
>problem.  Here's my theory on the wasserboxer:
>
>Frams are made with a tight filter fabric-- they rate the highest in 
>Consumer Digest type tests for fine particulate removal.  For the 
>most part this is a good thing, but a tight pore-space material means 
>higher back pressures given comparable surface areas (this isn't 
>entirely true but we'll ignore the rest of the facts).  In the 
>wasserboxer, i'm proposing that this higher back pressure jams the 
>engine's oil pressure relief valve to the top of its travel.  The 
>relief valve sticks there for a while, either due to the flow of oil 
>running past it or some 'stickiness' in the bore.  At rpms above 
>2200, there is still enough oil pressure to keep the system happy.  
>when the rpm drops to 2200, the warning buzzer activates due to the 
>reduced pressure.  Rpm below 2200 drops the backpressure enough 
>whereby the relief valve unseats and restores normal flow pattern and 
>pressure.  Additionally, oil light flickers at idle (a different 
>problem) could be caused by the restrictive filter material.
>
>So whaddya think?  sound like BS???   The VW service manager said 
>they are also seeing problems with "Valvoline" in addition to Fram 
>filters.  Installing the $10 Autobahn cures the problem.  :)
>
>-dan
>
>
>

In reality,  the FRAM filter has much less forward flow resistance than
almost any good filter available.  Are you using the right one, ph2870A?  If
you have a debris problem, you may be clogging it but if you engine is
healthy, the filter bypass will open allowing the oil to flow.  I would check
both oil pressure switches and possibly the control board,(burried in the
speedo head).  There is a switch between the push rod tubes on the drivers
side which requires tin removal to access. This is a normally closed switch,
held open by good oil pressure.  The control circuit ignores this switch
below 2000 rpm.  The other switch is below the water pump, (impossible to get
at). It is normally closed, held open by good oil pressure. This switch is
used all the time.  I would recomend checking oil pressure at the first
location with a gauge.  Should be >40psi, or more at 3000 rpm when engine is
hot.  If engine is filled with crud,(look inside valve covers)  pump inlet
screen may clog causing intermittant oil pressure problems.  Unfortunately,
this will require complete engine teardown to fix.

Dennis