V8 4.2 Carbon build up

[the_big_1]

Hi guys,

is the carbon build up on 4.2 V8 still an issue ? I am looking at a 2009 one to buy.

 

[Lloydie22]

I've heard its a problem with all the FSI engines. I have a 2009 audi S5 with 28k miles. But there are reports of these gunking up after the same mileage. I havent had any issues with mine. But then i don't have a clue what the intake valves actually look like as i havent messed about with the engine on this car... YET!

 

[Lloydie22]

carbon buildup s5 - A5_OC

 

[the_big_1]

Surprised if this is a known issue that Audi don't repair it or even offers good will gesture, like labour paid for, owner covers parts etc as this problem is no way down to the owner nor can the owner stop it happening.

 

[warren_S5]

They do in the US, but the UK dealers probably don't give a rats **** as it's a revenue opportunity

 

[desertstorm]

This problem is an issue with any car that uses direct in cylinder fuel injection, not Audi specific it's a side effect of the technology.

Ask An Engineer: GDI Problems In A Nutshell | The Truth About Cars

Karl.

 

[marshadee]

guys what are the symptoms to a carbon build up issue? My car seems to run fine, like ticking over is smooth, performance seems ok, but I've only had the car 2 months so I wouldn’t really know any difference. Could someone share show light on this please?

Thanks

 

[Statler]

Here's a link to the Dark Side, it should work for you.

Walnut Blast

It shows carbon buildup on an e92 and how it was cleaned. This 'walnut shell blasting' seems popular in the BMW circles.

 

[marshadee]

thanks mate

 

[the_big_1]

I would be interested too in the side effects of carbon build up. Only had the car a week and only thing I have noticed is tick over seems not 100% smooth and looks to be at about 650 - 700 rpm
Car has usual three month warranty as all traders have to give. Would Carbon build up come under the warranty or is it deemed normal wear and tear??

 

[Ian_H]

AZ Thread on carbon clean