[s-cars] S6 pinging woes - the continuation

Sun Aug 23 20:02:45 PDT 2009

Update:

Got my head back Friday from the machine shop - actually used a
different head that was in much better shape than mine - was supposed to
have bent valves - but machine shop said it was all good - didn't need
guides - just lapped in the valves and replaced seals.

Started on it on Saturday between many errands - put the last bolt on
the valve cover and found the hole was stripped - had to wait until
Sunday to get a hela coil to fix it.

Today - put the thing together, ARP head studs, multi-layer steel head
gasket, etc...

Took a while to get the valves pressurized - then noted coolant coming
from what seemed to be the water manifold...and then...noticed oil
coming out of what seemed to be the head - ok, I was freakin' out a bit
at this point...

However, doh! - I installed one of the half moons on the valve cover
improperly and the oil was going around it, dripping down the back of
the head and making it *look* like it was coming from where the head and
the motor meet. That was a quick fix.

However, had to take the intake manifold off to get to the water
manifold, sure enough I bunged up one of the o-rings putting the darned
thing in - doh #2...

Buttoned all that back up - and voila' she purrs like a kitten...:-)

I've got a boost gauge I want to install before I start cranking the
waste gate spring down - but its goes pretty good right now - woot!

Thanks to all for your advice and diagnostic assistance !

Its about a 6-8hr job without the need of any super specialized tools (I
did have to make a 6mm allen 1/4in drive socket for the lower manifold
bolts)...

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

-----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: Thu, Aug 13, 2009 8:31 pm
Subject: RE: [s-cars] S6 pinging woes - the continuation

U da man!!

Take a look here:
http://picasaweb.google.com/BlissRally/95S6HeadGasket?authkey=Gv1sRgCLTZ
_KHcwtL9bA#
<http://picasaweb.google.com/BlissRally/95S6HeadGasket?authkey=Gv1sRgCLT
Z_KHcwtL9bA> 

Now - couple of questions:

1.	the block - you can see in the pic the burn mark - any reason to
believe this will create more issues with a new gasket?
2.	the head - not nearly as noticeable burn mark - I would think
thi s would be fine.
3.	Pistons have some slop, I understand I can check this with a
feeler gauge? Anyone know the spec on it?

And finally, what causes this?

Thanks,

Vittorio -

________________________________

From: djdawson2 at aol.com <mailto:djdawson2 at aol.com>
[mailto:djdawson2 at aol.com <mailto:djdawson2 at aol.com?> ] 
Sent: Sunday, August 02, 2009 12:36 AM
To: Bares, Vittorio; t44tqtro at gmail.com <mailto:t44tqtro at gmail.com> ;
s-car-list at audifans.com <mailto:s-car-list at audifans.com> 
Subject: Re: [s-cars] S6 pinging woes - the continuation

Who's your daddy?  Who made the call?

Seriously, pull the head and take a good long look at the cylinder head
material between 4 and 5... make sure there isn't a groove burnt in it.
Also, take a very close look at the top of your #5 piston to make sure
that part of it isn't missing from the detonation.

If you're lucky, you will only find that the headgasket material is gone
between the cylinders.

BTW, you're not losing coolant, finding it in the oil, or blowing smoke
because your gasket is blown between cylinders, not between a cylinder
and the water jacket or oil passage.

Good luck.

Dave

-----Original Message-----
From: Bares, Vittorio <Vittorio.Bares at nuance.com
<mailto:Vittorio.Bares at nuance.com> >
To: djdawson2 at aol.com <mailto:djdawson2 at aol.com> ; t44tqtro at gmail.com
<mailto:t44tqtro at gmail.com> ; s-car-list at audifans.com
<mailto:s-car-list at audifans.com> 
Sent: Sat, Aug 1, 2009 8:42 pm
Subject: RE: [s-cars] S6 pinging woes - the continuation

Ok -

Compression Test (cold motor):

#1 155

#2 145

#3 125

#4 50

#5 60

Leakdown (warm motor)

#1 13%

#2 20%

#3 50%

#4 Near 100%

#5 Near 100%

When applying air pressure to #3, some air coming out of #4

When applying air pressure to #4, lots of air coming out of #5

When applying air pressure to #5, lots of air coming out of #4

So, head is going to need to come off - I'm just surprised I'm not:

a) eating *more* coolant than I am

b) have water in the oil, or oil in coolant

c) blowing billowing clouds of something from the tail pipe

Anyway, I'm hoping that I can just take the head off, replace the

headgasket (I have a metal one I can put on) and put it back on. Seems

to make sense to put some ARP studs in there - this is all best case

scenario - I guess I'll know more once the head comes off...

Comments?

Vittorio -

-----Original Message-----

From: s-car-list-bounces at audifans.com
<mailto:s-car-list-bounces at audifans.com> 

[mailto:s-car-list-bounces at audifans.com
<mailto:s-car-list-bounces at audifans.com?> ] On Behalf Of
djdawson2 at aol.com <mailto:djdawson2 at aol.com> 

Sent: Tuesday, July 28, 2009 1:00 PM

To: t44tqtro at gmail.com <mailto:t44tqtro at gmail.com> ;
s-car-list at audifans.com <mailto:s-car-list at audifans.com> 

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

 I believe that 30 minutes with a cheapo compression gauge is going to

give the answer... call it pre-ignition or detonation.

There are many documented cases of headgasket failure between 2 adjacent

cylinders.? The headgasket fails, then it burns a little groove in the

cylinder head between those 2 cylinders... allowing flame travel...

BTDT.

The one I experienced was between 4 and 5.? 5 was being pre-ignited.?

The result was an engine that sounded like it was "pinging" under any

and all conditions, even20idle.

Letting this go for too long will result in total failure of a piston.

I would urge you to do a compression test before doing anything else.

Dave

-----Original Message-----

From: Taka Mizutani <t44tqtro at gmail.com <mailto:t44tqtro at gmail.com> >

To: s-car-list at audifans.com <mailto:s-car-list at audifans.com> 

Sent: Tue, Jul 28, 2009 10:50 am

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

You've just contradicted yourself, Brett- if the fuel/air charge ignites

prematurely, you get a large increase in cylinder pressure, which causes

all

sorts of bad things to happen to the engine.

You've stated this below as well as stating that it doesn't.

Anyway, the bottom line is that it's bad, the OP may have damaged

his/her

engine and it should be checked out. Having that happen with all of the

high

boost mods taken out is a bad sign.

I'd also check the fuel system to make sure that you're getting the

proper

amount of fuel actually delivered- if the pump or FPR or injectors are

not

doing their jobs, the computer might think it's
 sending enough fuel when

it's not.

Taka

< pre style="background: white none repeat scroll 0% 0%;
-moz-background-clip: -moz-initial; -moz-background-origin:
-moz-initial; -moz-background-inline-policy: -moz-initial;">

On Tue, Jul 28, 2009 at 11:48 AM, Brett Dikeman

<brett.dikeman at gmail.com <mailto:brett.dikeman at gmail.com> >wrote:

>

> Pre-ignition does not increase cylinder pressures and temperatures

> much beyond normal values (I think).  Pre-ignition is bad because it

> puts more force on the engine internals, and in ways it wasn't<  font
color="black">

> designed...for example, if power is developed at exactly TDC, all the

> force goes against the rod, crank, bearings, and head gasket/bolts,

> instead of applying torque on the crank.  Detonation does increase

> pressure and temperature, massively- it melts and bends things.

>

> Cody's recommendation to drain/filter the oil and check the engine oil

> filter are sound.

>

> Brett

>

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