S8 V10 Carbon Cleaning

[M-A8]

Originally Posted by Norretal

Haha, I had an inkling at the time but thought you were just being helpful to others as is your way. I'm guessing the silencer delete enquiry was for your own purpose too.........good man, looking forward to your write up mate

yep
Going either tomorrow or Friday to remove two resonators.
I will do soon a S8 project thread covering all the bits done in the past couple of months so watch this space, plenty of engine p@rn and other ''stuff''

[M-A8]

Thread and pics are up.
A bit of a mess with the pics, but it was a rush job uploading it

http://forum.a8parts.co.uk/showthrea...437#post117437

[YorkshireBloke]

Hi,

Don't mind me but isn't the carbon from BURNED fuel, not the case on top of the valve??

Robert

[M-A8]

I'm not knowledgeable enough to explain how it happens, but V10's FSI engines suffer from it the same way as B7 RS4's and others (maybe not as bad).
My other 8, 3.7 V8 petrol did not suffer from carbon build up at all. It's all to do with the position of the injectors on them two engines.
Someone else will be along shortly to explain it properly

[Turbo Tony]

I read it was little remnants of oil that burned and turned into carbon.

[Delboy]

Yes picture the scene in the usual household oven where the oil spits onto the surfaces of the oven, then left uncleaned for months or years it gets baked on and is a bitch to clean.

Well the exact same thing is going on in the engine because the oil vapour is travelling from the crankcase to the combustion chamber for recycling.

On direct injected engines (fsi) there is no fuel to wash the valves of this oil mist so it get baked on.

[Turbo Tony]

OK, so Marcin's thread has got me tempted to do the clean myself, but I still find it really daunting. I've not yet ruled it out but I'm weighing up my options.

I spoke to the VWAS place in Harrow and they gave me their quote for the carbon cleaning today. They were marginally more expensive than the others, even after the introductory discount but I have to say he impressed me with his knowledge. Not only did he know the engine well, but I also struggled to get a word in when he started talking about flaps and airflow, which tells me he still has some enthusiasm for his work.

Our conversation got me thinking about injectors... Wouldn't it make sense to have them ultrasonically cleaned at the same time? I had them done on my Cavalier and even a particularly uninterested neighbour noticed how smooth the car was after having them done. It was a long time ago, but I remember the cleaning wasn't exactly cheap, and I'd be multiplying by ten this time around.

Thoughts? Anyone had theirs done? I'm wondering if it's worth it, considering the high fuel pressures run in Audis. Surely, they must stay reasonably clean anyway?