I use Mobil 1 15W-50 exclusively in my waterboxers.  The brand/grade
of oil is almost certainly not the problem.

The high RPM oil pressure alarm is a continuous tone.  You can easily
cause this by overfilling the crankcase.  Above the lower mark on the
dipstick is right.  As you approach the upper mark, you run a great
risk of having too much oil in the engine.  When this happens, the
crankshaft and associated parts can contact the oil, causing
splashing,  foaming, and low oil pressure.  When I change the oil, I
add oil until the level reaches the lower dipstick mark, then add an
additional 1/2 quart.

Mike

On Nov 17, 2007 5:15 AM, mordo <helmut.blong@gmail.com> wrote:
> Thanks, Ric. So, is it high pressure or low pressure warning? The sound I
> have is a continuous tone, not a beeping or pulsing.
>
> It seems to me that if it is in fact the pressure warning buzzer, it has to
> be related tot the change to the 15/50 Mobil 1. I wish I knew why that might
> be.
>
> cheers,
>
>
>
>
> ---------- Forwarded message ----------
> From: Richard Golen <rgolen@umassd.edu>
> Date: Nov 17, 2007 7:49 AM
> Subject: Re: What does the oil pressure warning buzzer sound like?
> To: mordo <helmut.blong@gmail.com>, vanagon@gerry.vanagon.com
>
>
> Hi,
>
> Sounds like the oil pressure buzzer. It is an annoying "high C" sound
> and starts when the engine hits 2500 rpm. The buzzer is located under
> the dash/instrument panel.
>
> You might want to check the connections to the oil pressure sending
> units - the one that sets off the buzzer (high pressure sender) is
> located near the crank pulley. The two sensors have a common
> connector to the main harness on the left side of the engine. To do a
> quick check on the high pressure sender, you can ground out the
> connector. If the buzzing continues, then there's a fault somewhere
> in the wiring harness. If it stops, then the problem may be with the
> sensor, or worse....
>
>
> Ric
>
>
> At 06:55 AM 11/17/2007, mordo wrote:
> >Fellows: I need some quick help because I'm leaving on a trip today and am
> >concerned about a sound alien to me. I posted at the Samba too so I've
> >pasted that below:
> >
> >
> > > Last night, I drove a 8 mile errand trip, stopping once. On my return
> > > trip, I was baffled by a sound I have never heard. At first I
> > thought it was
> > > interference on my radio as I was passing a group of television
> transmitter
> > > antennae. However it continued after I turned off the radio.
> > >
> > > The sound occurred twice and both times it was a slow crescendo to about
> > > high C. I can't say what RPM it occurred at for sure but I would guess
> > > around 2500 RPM. The sound seemed to stop when I let off the throttle
> but
> > > maybe it didn't stop immediately. The outside temp was about 40F.
> > The engine
> > > was well warm but not highway hot.
> > >
> > > A few days ago, I changed the oil from Castrol GTX 20/50 to Mobil 1
> 15/50.
> > > I always use a Mann filter.
> > >
> > > There was no flashing light. Is this the sound of the oil pressure
> warning
> > > buzzer? If so, it seems silly. It is too vague to be an alarm if
> > you ask me.
> >
> >Thanks in advance for the help.
> >
> >
> >--
> >mordo
> >1990 Carat
>
>
>
>
> --
> mordo
> 1990 Carat
>