Oil Pressure loss?

[WARATAP@aol.com]

 These pertain to my 1990 v8q with 203k on the clock, but could be for any
audi.

Oil Level = good.

Symptoms: 

When I first start the car in the day or after it has been sitting a while (1
hr) and I start her up (without fuss), the oild pressure guage reads between 4
and 5+, even at 2k.  Oil is 10-30 Mobil One and has been for years (except
Castrol Syntec once). Oil regularly changed (even more so with that go@#$%%rn
leak).

After driving around a while water temp guage reads between 60C and 100C (80?)
-normal.  Oil temp (as forever, reads first notch over 60C. But Oil pressure
reads lower.  Iknow, its normal once the heats up for the pressure to drop.
But now when idling it drops to 1/2 bar (would that be 8 psi?), and even when
reving motor to 3k, won't go past 2 bar.  

Methinks:  

1)Faulty gauge or sending unit (should test -where on this car)

2)Main bearings going bad (possibility, though she purrs like a kitten at 750
rpm)

3)Bad Oil Pump

I'd prefer 1)bad sending unit, that would read false resistance values as it
gets hot, and that wouldn't surprise me (anyone know the desired values -like
I could check!)

Any experience would be helpful as I press my luck some more.  The audi gods
have been pretty kind to me so far :-)

or is this why Brendan just dropped off my 4kq this week...

-Ingo Rautenberg