90Q BVAU ( TAP TAP TAP NOISE) Part II

[J Kurt Bonk <KaBonk@mindspring.com>]

I had a loud tap from the top of the engine(thought valves)...local audi
guy said it was worn lifters........... I was informed by a lister that
the Brake Vacuum Assist Unit, on the drivers side of the engine
sometimes made that noise.  I cleaned the unit but still had a tap in
cold weather.  Using my polish mind I turned out the retainer bolt to
the spring 1.5 turns, to apply more pressure on the plunger, which rides
on the camshaft............so far NO noise........Did I find something
???????

Part II
This morning the tap was reduced to about one minute, from cold to I
hear it to its gone.  I got in there this afternoon.  ( life as a
selfemployed)

I took the other end off.  The retainer bold is attached to a flat disk
which moves in and out creating the vac.  This travels in a oil bath,
and is held in place with a~11mm nylon lock nut,  ( so I was wrong the
retaining bold spins freely) I turned that 11mm nut out a bit and it
seems to helps. So far so good, this might need to fill up with oil so
it might take a few minutes of driving. (very small oil passage)

I think the gods provided three problems. one the cam follower is solid
material, and might be wearing, I think the tolerances might be too
tight, and the small oil passage reduces the flow of damping oil?  the
return is huge! Thus any wear might provide the tick tap or something. I
wonder if when I rotated the bolt if it changed the wear area, reducing
the gap? 

Maybe all we have to do is get a new follower? dose anyone know the
lenght of this unit NEW?  Is there anything in Bentely about this unit?
are they using the BVAU on a latter model engine ?
ARGGGGGGGGH
-- 
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J. Kurt Bonk
353 Reno Street
Philadelphia, PA 19123
215 625 2661

16 Deer Run 
Big Flats, NY 14814
607 562 3351

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