[s-cars] S6 pinging woes - the continuation

[djdawson2 at aol.com]

 If you're going to have the head rebuilt, replace at least your exhaust guides.  They wear the worst, and cost relatively little to replace.

At 235k miles, yes, there will be some piston/cylinder wall "clearance."

I think the head gasket is bound to fail sooner or later in high boost applications.  I just think that between 4 and 5 is the weakest link.

Dave


 


 

-----Original Message-----
From: Bares, Vittorio <Vittorio.Bares at nuance.com>
To: djdawson2 at aol.com; t44tqtro at gmail.com; s-car-list at audifans.com
Sent: Fri, Aug 14, 2009 1:06 pm
Subject: RE: [s-cars] S6 pinging woes - the continuation





























Nice!



 



I’m having the head decked, valves
re-seated, and new seals – that way the machine shop will be able to look
at it and see if there’s anything worse going on…



 



ARP Studs will be here on Monday. Gaskets
ordered today.



 



Everything I’ve read so far says
that I5 piston slop is normal as hot dogs and apple pie in America…



 



Emery cloth sounds good – I’ve
also heard that a sharpening stone is another way to go?



 



So the failure is due to excess heat –
thereby *melting* the HG?



 






Vittorio -



















From:
djdawson2 at aol.com [mailto:djdawson2 at aol.com] 

Sent: Friday, August 14, 2009 2:53
PM

To: Bares, Vittorio;
t44tqtro at gmail.
com; s-car-list at audifans.com

Subject: Re: [s-cars] S6 pinging
woes - the continuation






 






1) Your block should be fine.  Spend some time getting
the surface of the block cleaned up... emery cloth will do fine.  You
shouldn't find any actual metal damage on the surface of the block.







2) Clean your head up as well.  However, there is a very good chance you
will find metal damage on the head.  If you can catch your fingernail in
the burn mark, get it welded up and then resurfaced.



3) Your pistons look good.  Based on the pic, it doesn't look like #5 got
hurt at all.  This is very good news.  Forget about the
piston/cylinder slop... unless you intend to consider rebuilding the bottom
end.  If the engine performed well prior to this failure, it will be fine
after you repair it.



Why this happens?  I couldn't state any facts, but would speculate that it
is a combination of high boost along with the Audi I-5 engine's tendency to
build more heat at the firewall (#5) end of the engine.



Good luck with the repairs.  Oh... and consider using ARP studs on your
head (this is a test to see if QSHIPQ is reading).



Dave