Re: Valve noise

[Eliot Lim <eliot@lanmola.engr.washington.edu>]

> This is a fact of life with these engines as far as I can tell.

i second that.

> It might even be worth speculating that Audi was pursuing a design
> goal in making the lifters weak, intended for Autobahn and all that,
> but they supplied solid lifters outside the U.S., so maybe a little
> less overlap at low rpms help emmissions.  Maybe they just botched
> it, as with the exhaust manifold/gasket situation.  Nonetheless
> they do work as advertised when held to the specification supplied.

no, the european ones are the same way.  most long term tests on
VW/Audis in the british rags mention the clatter.  the conclusion that
they give is that it is "normal".

in my experience the clatter is somewhat dependent on oil viscosity.
thick oils produce more clatter than thin ones.  maybe this is a good
time to try castrol syntec 5W-50.  it is great stuff in cold weather.
i'm on my first sumpful and there's noticeably less friction with a
cold engine and oil pressure and temperature are pretty stable when
hot.

finally, here's some related trivia.  for the v8 engine, which is
essentially two siamesed 16V 4's, they added a secondary oil reservoir
near the top of the heads to lube the lifters immediately at startup.
thus this engine never clatters.  somewhat of a hack if you ask me,
but i'm not clattering about it.. :-)


eliot