re:Hydraulic Lifters

[cmice@mke.ab.com (Christopher Ice)]

>I'm sure this is old hat for most quattroeurs, but I'm unable to find the
>answer in the faq.  Here is my question:  how serious is that
>clickety-clack sound at startup?  Do you just live with this?  Do you
>change the oil viscosity?  Are the valves adjustable?

The noise you hear is probably the lifters.  It doesn't appear to hurt
anything, but it IS annoying.  They aren't adjustable, therefore the
"benefit" of hydraulic lifters.

I also have a "vacuum pump" theory, which I'm developing on my '88 90Q.
However, this seems to cure (temporarily at least) a TAP, TAP, TAP noise
that occurs randomly...not necessarily on startup, hot or cold, just
random.  One of these days (when the temperature isn't 2 deg F), I'll be in
the right place at the right time to record it.

It is embarassing, but short of replacing the lifters, there's not much
that can be done.  There has been much debate over whether oil is a factor,
but nothing conclusive has been determined.  I tried synthetic in mine (for
the random tapping), but that really didn't seem to make a difference.
Might be possible to add an electric oil pump to pre-pressurize the oil
system (aftermarket add-on for turbo cars, to prevent shaft wear) but that
could be an expen$ive proposition (more expensive than new lifters).

In short, however, there doesn't seem to be any harm done by the noise and
it's difficult to get rid of.

Chris

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