[V8] Oil Seals

[urq]

... first off ... Welcome aboard Ron!

... not to seem too condescennding, but if you think about it, if most
"garage techs" knew that much about how things really worked inside engines
they probably wouldn't be "garage techs" ... obviously they do tend to have
a lot of practical knowledge, but you still need to apply a bit of critical
thinking to what they might tell you.  My immediate response is .... that
could be possible if you allowed pressure to build up in the crankcase ...
but that shouldn't be happening, should it?  The crankcase ventilation
system is supposed to ensure that little if any pressure builds up in the
crankcase.  Who knows for sure what the mechanism could be ... frankly I
wouldn't dare to claim my own capabilities to be any better than those of a
"garage tech" myself ... but one thing I have noticed over the years is that
when you mess with one thing, it can create issues with another related bit
that may have been working fine beforehand.  Whatever wear mechanism created
the leak on the RMS certainly should be occurring on the front crank seal
too ... could it be that the crank has shifted ever so slightly?  Could have
been due to whatever unusual motions and accelerations the engine was
subjected to when the rear seal was replaced?  Who knows, but I would not be
surprised to hear of it happening ...

What I can say is that there are several seals at the front of the engine
that might well be leaking ... in addition to the crankshaft seal there is
one for the oil pump drive which has been known to leak as well.  What would
probably be best would be to consult with someone who is familiar with the
V8 engine ... such as various members of this list ... or pros like Keith T
at AudiConnection in Virginia (?), Stephen Nechodom at KarMechanix (sp?) in
Berkeley or Mike Rooney at Ingolstadt West in Southern California.  I
suppose that Chris Semple from Force5 down east, Scott Mockry in the PNW,
Scott Justusson in Chicago and 2Bennett in Davis, CA would also be
possibilities.  I'll bet others will chime in with other Audi V8 informed
techs in other areas ...

It sounds as though you might not be too afraid to get your own hands a
little dirty ... if so you might want to get a copy of the service manual
and do it yourself.  The thing is that if you are contemplating front seals
you might want to investigate when the timing belt was last replaced ... and
consider doing that wheile you are in there ...

Steve B
San Jose, CA (USA)

> Hi fellas,
> Pretty new to the mailing list and I'm hoping that maybe some of you can
offer some words of advice.  My question is, can replacing the rear main
seal cause other engine oil seals to weaken and leak?
>
> I knew that my rear seal and valve cover gaskets were leaking.  I asked a
local garage (that was recommended) to fix the "oil leaks."  Well, I got my
car back after having the rear seal replaced (I did the valve cover gaskets)
and my car was still leaking oil.  The garage determined that it was now the
front seal leaking because replacing the rear seal caused "pressure to crack
the front seal."  Is this guy for real?  My problem is, I knew the rear seal
and valve cover gaskets were leaking when I brought it in, but didn't think
to look for any other leaks beyond that one.