Hi everyone, first time poster here. Looking at picking up a c6. I found some good deals on some 4.2 FSIs and the odd 3.0t, but I found a fixxer upper S6. It has 250,000km according to the add, some JHM parts on it, and intake flaps deleted. I talked to the owner and he said “cylinder 10 is scratched”. There’s a bit of a language barrier so I don’t know if that means it’s just not firing or its damaged and the block/cylindsr needs to be repaired. I was wondering worst case scenario if these engines are able to be overbored if there is piston/cylinder damage, and how common engine failure on these 5.2s are? I know I’ll probably be told to just go with an A6, but I don’t think one for this cheap will show up again.
On here we love the S6 and all of the Audis so no body is going to tell you to do this or that. We’re all real car people here.
The cylinder 10 is scratched is not something I have ever heard of. So it’s hard to say what that could be. A few good things. If there is JHM parts on the car there is a good chance that the member had read or been on here. The intake flaps being removed isn’t a good thing as it clearly means that the intake is damaged and needs to be replaced.
If you’re looking for help I would start with where are you located and how much do they want for the car. What hear is it and can they perform a compression test for you at an independent indy shop.
Its a 2007. I’m near Ottawa, Ontario and the car is about 4 or 5 hours away in Quebec. He’s firm at 3 grand. He doesn’t seem to think it’s low on compression or anything, but runs rough and according to him seems like it’s burning some oil. From the research I’ve done, these engines seem to be fairly reliable, other than the intake manifold flap issue and typical direct injection problems. I’ll see if he will send me a startup/running video of the car, ffor3k I don’t think he’s willing to take it to a shop for a diag.
In my experience and on my S6 this was due to a faulty PCV system.
So it could be a cheap thing.
Early 2007 or late?
Because they did change something in the early production and the first cars had problems with the back cilinders.
My car had a replacement engine by audi at 20k miles for rear cilinder damage causing high oil consumption.
I’m in Europe for reference maybe it was only here but I’ve seen other cases as well.
Thanks for the input guys. The owner has a couple of people coming to look at it tonight, if that falls through I will go see it tomorrow. Just deciding if I should go up with a truck and trailer and buy it on site or just have a look. Hopefully I didn’t give the car up by posting about it and someone on here is coming to swoop it up 
Do you have a vag com? I would take a vag com with you and check to see if there are any codes. If there are not codes when was the last time the codes were changed. Cylinder wall scoring isn’t something that you hear a lot about but as dzow said some of the early cars had issues.
I would be careful and check over as much as you can. for 3 grand if the car runs and drives without a CEL. It’s hard to pass on that. You could find a used motor and still have less in the car then most of them go for used.
BUT I would say plan on spending about 3 or 4k on the car getting it up and running 100%
Injectors are A MUST if he didn’t do it already.
Carbon clean.
New PCV system as mentioned.
Check the production date on the coils and plugs
probably going to need a new coolant tank and Y fitting.
New O rings for the oil filter housing and then the valve cover gaskets.
and then the new intake manifold.
Well I think the ship has sailed. Owner is now ignoring my messages. Oh well, I guess I could settle for a 4.2 fsi or 3.0t C6. It would have been a cool car. Maybe down the road another one will pop up. Thanks everyone for your input, used to people on forums where I would be steered away because the car would need work so therefore not worth it, hate that mentality
We are excited about cars on here and we’re here to all work together.
Performance wise. The S6 would have been the most exciting. But with JHM recently doing a lot with the C6 that can be a really exiting substitute… and the 3.0t and 4.2 programs are some of the best supported as they just like the S6 come with ECU and TCU options.
While the 5.2 is a once in a lifetime opportunity due to just how unique the motor is you can really enjoy the other C6 options until find another deal.
If you really have your heart set on the 5.2… Just take some time and dig through the internet. The 5.2 offerings in both the S6 and S8 are mechanic minded cars at this point.
Feel free to check back in and let us know how your journey ends.