Thanks B6JoeS4 and Meistah… I added the link to the carbon section. Great first hand experience.
S6 horror story
Owner buys used 08 S6 with 21k miles. Car is consuming oil. Has dealership run oil consumption tests and finds 1.8Qrts of oil consumed every 1000 miles.
Dealer investigates further and finds cylinder wall damage. Diagnosis: engine replacement needed
How terrible. I’d see if you can just get pictures from him and post them here.
How are the pistons and rods made…cast? I think I read that up above
Yes, I have messaged him about getting pics, and will post them here if he sends them.
Ill see if he has any info on the car history too.
The study guide says forged rods and cast pistons
[b][i]Connecting Rods
The connecting rods are a familiar trapezoidal design
forged from 36MnVS4 high-strength steel. This
design reduces oscillating masses and distributes the
combustion force more evenly.
The lower end of the connecting rods are cracked after
forging. During the cracking process, the connecting rod
is split at a predetermined breaking point using a special
tool. The resultant unique breaking surface ensures the
high joining precision of the two mating parts.
The connecting rods are cross-drilled to allow engine oil
to lubricate the rod bearings and piston pins.
Pistons
The cast aluminum pistons are manufactured by the firm
Kolben Schmidt. They have a special piston head design
that supports the FSI combustion principle. The design
aids in the tumble effect of the fuel mixture during its
intake stroke.
The piston skirts are electro-coated with a special ironbased
friction reducing material to minimize wear under
load.
Spray jets located on the engine block provide cooling to
the underside of the piston and the piston pins.[/i][/b]
great info there^^^
that’ll explain part of the cylinder wall scoring
Audi went with forged pistons on the 4.2 FSI RS4 and S5/Q7 engines, likely in part to help alleviate some of the scoring problems they had on previous NA engines.
Interesting. I will do my best to keep track of how many of the S6’s this is effecting, and to what extent. There are very few stories of complete engine replacement being required, but many accounts of the S6 v10 consuming more oil then the average engine.
JE does make forged pistons for the R8 and Lambo 5.2 v10s, so they may work with the S6. They drop compression to 9.0, as they are designed for adding forced induction. If you already have damaged the cylinder walls though, these are obviously not going to help until you repair that first.
http://www.jepistons.com/Catalogs/Sport-Compact/Lamborghini.aspx
http://www.jepistons.com/Catalogs/Sport-Compact/VW-Audi/R8V10.aspx
https://www.youtube.com/watch?v=N1YcDnBvOT4
Ill have to ask CV if he has any more info on this. I think he mentioned that there is a way that minor scoring can be fixed, to a certain extent.
Also, I have heard that JHM is working on a resleeving program for the Audi alusil blocks. There is a sleeve kit for the Lamborghini v10s, priced at a cool $5k !!! Labor not included 
http://www.titanmotorsports.com/lamborghini-gallardo-sleeves.html
the JHM program is pretty deep, and I’d guestimate they’re over $100,000 in R&D. Maybe double that. I don’t see them trying something similar for the 10ers because it’s such a limited market.
Wow! That is quite the investment. Great for the v8 guys.
And yeah, I agree, the v10 market is practically nothing. Cars with the cast pistons would be the S6 and S8 v10, with the Lambo and Gallardo getting forged ones stock, and nicer forged rods (like the RS4). I think it will be interesting to see what happens to the v10 S6/8s. Will they just quietly fade away and be forgotten? Probably. The only thing that REALLY differentiates them, the v10, was not well executed in stock form, and has become quickly overshadowed by the more recent smaller, FI engines from Audi.
If the aftermarket (i.e. JHM in this case) can really open up the performance of these cars, while addressing some of the shortcomings, then you may have a small group of enthusiasts who keep them alive. Otherwise, they will probably just disappear into the junkyards of North America. Only JHM can save the species from extinction !!! LOL
yeah, they’re really interesting, and when I see one it’s always such a rare beast.
getting a nicer tune, opening up the cats, and putting a good sounding resonated catback on them makes it a really cool comfortable cruising car. If you can trap 110 in one, at 4350 lbs and with all that space and luxury, that’s a really cool car for the segment.
I think that 110 trap is an obtainable goal. jp2.7v6tt was nice enough to send me the following info (which I haven’t included in the S6 info dump, just because I am trying to keep performance results to official track times):
We used the performance Box vBOX , went from 105 mph (stock) to 109 with out cats and with a complete tuneup and carbon clean , its goes side by side with a 5000 miles rs4 …and over 220 km the s6 start to pull , I really think with a 3 inch exhaust and a good tune this car can go 112+
Something that I noticed in the sleeves for the Lamborghini motors was that they mentioned the v10 Lamborghini motors already had some sort of liner. You’d think that’s an important thing to have and important information to know if that’ll be something that separates the Audi and Lamborghini motors even more.
Ill try and get confirmation on that. When JE lists its pistons for the Lambo 5.2, it mentions Alusil bore. The whole purpose of Alusil is to have no sleeves, isnt it?
LAMBORGHINI GALLARDO V10 5.2L FSI 2009-2012
ASYMMETRICAL FSR FORGING Std Bore: 84.5mm (For use with STD Alusil Bore)
This document seems to confirm that the Lambo v10s have a Alusil block
Today, KS Aluminium-Technologie has the following low-
pressure die cast cylinder blocks in series production:
Audi V6, ALUSIL
®
(various versions)
Audi V8, ALUSIL
®
(various versions)
Audi V10, ALUSIL
®
BMW / Rolls Royce V12, ALUSIL
®
Lamborghini V10, ALUSIL
®
Aston Martin V8, hypoeutectic secondary alloy with
shrunk-in grey cast liner
Porsche Boxer
6
, ALUSIL
®
(various versions)
Porsche V6, ALUSIL
®
Porsche V8, ALUSIL
®
VW / Audi / Bentley W12, ALUSIL
®
the Lambo V12s have liners
http://www.carbuildindex.com/wp-content/uploads/2013/11/3-Gallardo-Engine-Assembly.jpg
this page claims to be for rebuilding the Lambo V10, pictures of the bare block
http://www.carandclassic.co.uk/car/C287880
another low quality picture
http://t2.gstatic.com/images?q=tbn:ANd9GcSX0YIRlouVXYcYUvG9eNyQNUcT7XP0doXTMk7RjWqnkLWfW59o6A
What’s to be taken from this then? The company selling sleeves for the motor mentions the Lamborghini blocks have liners.
[quote]With this increased power comes increased cylinder pressure and the factory cylinder liners typically become the weak point.
[/quote]
Not sure. Everything that I see aside from that seems to indicate an alusil block without liners.
Contact the member from AZ with the bad block maybe you can get pictures or a good deal on his bad motor.
I did contact him about pics. Haven’t heard back.
Ill msg him about the engine. But, I bet that the shop just list it on car-part.com or ebay for $5k and neglect to mention the problem with it. It would only be worth getting for testing if you could get it for a thousand bucks, IMHO. We should mark the serial in case it shows up again down the road in a different car.
Who knows the real history of the car. For all we know, it is a high-mileage engine after the car had a front end collision. Or maybe a flood car. Engine replacement at 21k miles doesn’t make sense to me. I only mentioned it here so that we can track any major issues, and look for trends. So far, this seems like a one off occurrence. I saw one similar story in the UK awhile ago. Ill see if I can find it.