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Re: lifters/valves, and vaccum pump noise

Got brave and took the pump off over the weekend.  Took it apart and
cleaned it, put it back together and it seemed to be quiet.  However, I
heard faint knock this morning, so perhaps it is the rod that drives it.

I looked all over in the Bently manual and see NO REFERENCE to it all.  In
fact, in pictures where you would see it, it is shown removed...but no
pictures of it at all.  What the hell is it for???

I did see the rod.  Perhaps it shortens somewhat with wear.  I think that
can be adjusted out by losening the honking nut that holds the spring in a
little.  Should make the pump shaft slightly longer.  Anyone know about
finding a new rod?

Details on the pump if requested.


>This subject has come up before.  If you have a 90 or a 4000 you
>probably have a vaccum pump.  When they get loud they make a clakking
>sound that is easily mistaken for lifters.  They are expensive to
>replace.  A better solution is to have the thing taken apart and
>cleaned.  We have had this done once on our 4000Q and it takes care
>of the noise.  Apparently they fill up with oil and need to be cleaned
>and drained.  Sorry I can't provide more details, I've never actually
>done it myself.   We had our lifters replaced too but the clattering
>came back 6 months later.  It turned out as long as the car doesn't
>sit for extended periods of time, and the oil is kept clean, and
>with an Audi oil filter with a check valve, the clattering doesn't
>come back.  btw, I hear the vaccum pump costs $700+....
>There was talk of running a cleaner through the system but I haven't
>heard of any success stories so far.  Using Slick 50 initially made it
>better but eventually it just seemed to get worse.
>> From: Eric Glanz - Unix Support <UCSEDG@uwplatt.edu>
>> >He says it's usually the vacuum pump - there is a rod inside that
>> >wears, and that is what produces the noise.  They don't usually
>> >fail he says, but just get louder and louder.
>> Do you happen to know what rod he is talking about?  Is it the rod
>> that drives the pump from the cam, or a rod internal to the vacuum pump?

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