Low Oil Pressure Indicator Light on 86 4kcs Q

[Chad Frederick <fredie@u.washington.edu>]

Heres My Question for the list,

	Ok this is the story, I changed my oil about 2 weeks ago on my 86 4kcs Q.
I used 10-40 castrol dino juice and a non-OEM oil filter, but by no means a
low quality oil filter (I waiting for the OEM filters to get here from
Blauf).  Everything is fine for about a week when the low oil pressure
light comes on and buzzes while I am driving above 2000 rpms for about 4
seconds.  I think nothing of it since, I thought it could be the oil filter
not having the correct oil flow parameters for an Audi.  The indicator
light did not reappear until exaclty one week later.

	Now today while on a scenic cascade drive the buzzer repeatedly came on
several times for 10 or more seconds each time and would then quit.  It
only came on sparacticly and would not continue for very long.  I checked
the oil and it was not low at all as it was the first time the the light
came on.  I then began to notice at higher rpms (above 2000) a light
clacking sound coming from the motor and after that as well as when it
idled.  Because of the clacking I ruled out a defective sender unit.  The
Engine is not overheating.  I do not think it is the oil filter being
clogged since it is just a couple of weeks old.  

	So, I believe it to be one or more of several things:  
-Oil pick-up strainer defective (can you just pull the pan and clean this?)  
-Oil pressure relief valve defective.  (I do not know what this is)
-Oil pump is worn or the mountings are loose. (would the light stay
permantly on if this was the problem?) Is this the symptoms of a bad oil pump?
-Worn main or big-end bearings.  (I do not know what this it)

Given all the symptoms what do you think it is?  If know or you have had
this happen to you please respond and explain where I should check next to
find out what is faulty.  I will not drive the car until it is fixed so no
further damage can occur.  

Thanks for your advice,
Chad Frederick
86 4kcs Q