[s-cars] S6 pinging woes - the continuation

Fri Aug 14 12:17:02 PDT 2009

 Your MRC software will certainly NOT be running lean.

High boost = high cylinder pressure.? I think it is simply inevitable that something will fail, and the 4-5 cylinder area is the weak link in terms of temperatures.

Dave

-----Original Message-----
From: Bares, Vittorio <Vittorio.Bares at nuance.com>
To: Jerry Scott <jerryscott at wispertel.net>
Cc: s-car list <s-car-list at audifans.com>
Sent: Fri, Aug 14, 2009 12:56 pm
Subject: Re: [s-cars] S6 pinging woes - the continuation

High boost? Check!!

I'm installing a boost gauge so I can see what the car is running given
the SW it has and the wastegate adjustment - I've only put about 2500mi
on this car - so don't have a clear history - but it is Stage 3 MRC, RS2
and has been boosted for about 80k miles...(maybe more - currently has
235k)

I may put a wideband on it when I get it back together just to see if it
has any lean spots - but I understand MRC software is pretty good/safe.

Also, now that it will be intact - I think performance might be pretty
darn good without having to crank the waste gate too much (it was pretty
darn good with a bad head gasket :o )

Thanks for the info - I guess I'm still curious though how the high
boost makes that happen?

Vittorio -

-----Original Message-----
From: Jerry Scott [mailto:jerryscott at wispertel.net] 
Sent: Friday, August 14, 2009 1:08 PM
To: Bares, Vittorio
Cc: s-car list
Subject: Re: [s-cars] S6 pinging woes - the continuation

I think that Dave Dawson will likely tell you that this is caused by
running 
high boost in excess of 25 psi on this small engine.
Jerry

----- 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: Thursday, August 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
> this 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]
> Sent: Sunday, August 02, 2009 12:36 AM
> To: Bares, Vittorio; t44tqtro at gmail.com; 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>
> To: djdawson2 at aol.com; t44tqtro at gmail.com; 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
>
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>
> #2 145
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> #3 125
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> #4 50
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> #5 60
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> Leakdown (warm motor)
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>
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>
> #1 13%
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> #2 20%
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> #3 50%
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> #4 Near 100%
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> #5 Near 100%
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> When applying air pressure to #3, some air coming out of #4
>
>
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> 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...
>
>
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> 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?> ] On Behalf Of
> djdawson2 at aol.com
>
>
>
>
> Sent: Tuesday, July 28, 2009 1:00 PM
>
>
>
>
> To: t44tqtro at gmail.com; s-car-list at audifans.com
>
>
>
>
> Subject: Re: [s-cars] S6 pinging woes - the continuation
>
>
>
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>
> 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.
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> The one I experienced was between 4 and 5.? 5 was being pre-ignited.?
>
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>
> The result was an engine that sounded like it was "pinging" under any
>
>
>
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> and all conditions, even idle.
>
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>
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> Letting this go for too long will result in total failure of a piston.
>
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> I would urge you to do a compression test before doing anything else.
>
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> Dave
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>
> -----Original Message-----
>
>
>
>
> From: Taka Mizutani <t44tqtro at gmail.com>
>
>
>
>
> To: s-car-list at audifans.com
>
>
>
>
> Sent: Tue, Jul 28, 2009 10:50 am
>
>
>
>
> Subject: Re: [s-cars] S6 pinging woes - the continuation
>
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> 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.
>
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> You've stated this below as well as stating that it doesn't.
>
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>
> Anyway, the bottom line is that it's bad, the OP may have damaged
>
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> his/her
>
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>
>
> engine and it should be checked out. Having that happen with all of
the
>
>
>
>
> high
>
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>
> boost mods taken out is a bad sign.
>
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> I'd also check the fuel system to make sure that you're getting the
>
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> proper
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> amount of fuel actually delivered- if the pump or FPR or injectors are
>
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> not
>
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> doing their jobs, the computer might think it's sending enough fuel
when
>
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> it's not.
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> Taka
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> On Tue, Jul 28, 2009 at 11:48 AM, Brett Dikeman
>
>
>
>
> <brett.dikeman at gmail.com>wrote:
>
>
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>>
>
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>> Pre-ignition does not increase cylinder pressures and temperatures
>
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>> much beyond normal values (I think).  Pre-ignition is bad because it
>
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>> puts more force on the engine internals, and in ways it wasn't
>
>
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>> designed...for example, if power is developed at exactly TDC, all the
>
>
>
>
>> force goes against the rod, crank, bearings, and head gasket/bolts,
>
>
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>> instead of applying torque on the crank.  Detonation does increase
>
>
>
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>> pressure and temperature, massively- it melts and bends things.
>
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>>
>
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>> Cody's recommendation to drain/filter the oil and check the engine
oil
>
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>> filter are sound.
>
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>>
>
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>
>> Brett
>
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>>
>
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>
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> _______________________________________________
>
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>
>
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>
>
>
>
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