Ben,

I have recently got the oil pressure buzzer.  I'm thinking along the
line of the pressure relief valve sticking when some conditions are
right.

My conditions seem to be, high rpm then lower as I crest the hill,  hot
oil temps as in a longer than three or four minute climb, and heavily
loaded.

Some observations that may or may not be relevant.  My breather hose is
collapsed somewhat.  My van has also made a sudden valve noise, as if
several lifters momentarily collapse.  The oil is 10-40 mobil synthetic.

Sincerely,

Mark Keller
91 Carat