HELP! Dead 535i!

[Bmwbig6@xxxxxxx]

Hi everyone,

I am in desparate need of help from you guys.  I was driving my 1990 535i
(132K miles; 5-speed w/ Conforti chip) in first gear when the car just died as
I made a left turn through a residential neighborhood.  There was no warning,
sputtering, stalling, or bucking.  The car just fell silent and I slowed to a
stop.  I tried to restart it, but it wouldn't start after extended cranking,
and the street was too flat to try and pop the clutch.  I have no error
messages on my check control display when I try and start the car, but I
remember seeing the words: "OIL PRESS SENSOR" flash right after the car died.
I looked this error code up in the owner's manual, and not surprisingly it
instructs me to "consult BMW dealer" because the part is "defective."  (Thanks
for being so specific!)  I know it's not the oil level because it's right
below the full mark on the dipstick.  The only other weird thing I noticed is
that when I turn the key into the accesory position before attempting to crank
it, I hear a bunch of whirring and clicking noises coming from under the dash.
These noises sound very consistent and repeat indefinitely until I turn the
key all the way over or remove it.  I recognize them as computer/relay and
motor noises, but they've never sounded this crazy and rhythmic before.
Anyway, I have a few questions for this digest:

1) Has anyone else experienced this sort of problem with their BMW (especially
big sixes)?

2) Where is the oil pressure sensor located, and is it possible that a wire or
contact is just loose?  Can it be tested or cleaned or something? (I know, fat
chance)

3) Any idea on how much one of these doodads costs if I can't replace it
myself?

Thanks in advance for any advice, tips, and help you all can provide!

Ben Trapp
bmwbig6@domain.elided

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