Ken,
How Odd!  The exact same thing started with my 87 Wolfsburg this week also.
It started offically last Sunday.  I started it up after it had been sitting
about 8 hours.  I put it into Drive, pulled away from the curb, and as soon as
the auto trans shifted from first to second, the buzzer came on.  I pulled
over immediately and did the same checks that Kirk did.  Everything looked OK,
The levels were good and there were no leaks. I restarted it and drove 20mi
home.  I didn't hear from it again for two days when it did it under almost
the same conditions. Coming out of work, after sitting for 8 hours or so the
light and buzzer again came on when shifting from 1st to second.  This time I
pulled over and put it into Neutral and revved it a bit to see if that would
bring up the oil pressure, but it stayed on.  I put it back into drive and
drove off and it stayed on.  When I hit the next red light, I turned it off
and re-started it and didnt hear from it again.  Thursday I did an oil change
with a MANN filter and didnt hear from it all day.  Yesterday, after work
while shifting from 1st to 2nd (seeing a pattern here aren't we?) Buzzer and
light appeared again this time I kept driving and after no more than 3 mins of
buzzing, it went off by itself.  I havent heard from it since.  I, too would
be interested in any theories as to what is causing this.
Keith
VintagePkr@aol.com
87 Wolfsburg Vanagon
85 Diesel Golf
80 Diesel P/U (FS)
79 Champagne Ed Bus "Buzzo" (FS)
78 Partz Bus (FS)