Audi's official answer to carbon build up

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Surprised at the coking inside the combustion chamber. Must be that even though fuel is getting in there as it's injected right at the last instant it doesn't have chance to let the detergents in the fuel properly clean the inside.

[pad125]

Look at how much crap is sitting in the valve seat. My understanding is that as soon as the smallest amount of carbon lodges itself in the seat and keeps the valve open on combustion then its all over. The valve stays open and the carbon keeps building up, keep the valve open more allowing more blow back and hence the pictures.

My car didn’t seam to suffer for power, in fact it was pretty much on the money with MAC’s car and P_G’s when we all went on the Euro trip. My problems started when it went in to the dealer for an MOT……£2k lighter and I’ve got my back with a valid MOT

[RS6chris!]

Let me know when someone has a solution and I wont have to spend thousands getting it cleaned again

If someone thinks they have a system to clean this effectively without taking the heads off then I'm in

Give over!!! Nothing a regular italian tune up cant take care of....44k of town driving that!!!

Mine looks nothing like that..clean as a whistle..i drive my car like i stole it...

Stop panicking!!!

[PetrolDave]

Give over!!! Nothing a regular italian tune up cant take care of....44k of town driving that!!!

Mine looks nothing like that..clean as a whistle..i drive my car like i stole it...

Stop panicking!!!

+1

[pad125]

I’m not panicking guys, in fact my panic is over. Engine out and cleaned so I’m done! I do drive a lot in town, London to be exact which as we all know is slowest traffic cycle in the country. But what are we saying here, “the cars not fit too be driven in town“!!!! I’d like to see that on the next RS sales brochure. And as for driving it like I stole it, believe me, I’m no driving Ms Daisy! But I don’t think “I was only keeping my engine cleanâ€

[aidanjaye]

With all due respect fella's, power is not the issue here (as much as we all love the kick in pants the RS4 gives us), the issue is restrictive inlet tract. Take your car to the MOT station and ask them to do an emissions test and see how close you are to the limit. I'm guessing its varied but a also a lot closer than is close for comfort. If my car is one off then thank the lord its all a lot of hot air about nothing but if its not be prepared for the worst.

Mines just had emissions test and is way under limits - standard car with 40K.

[aidanjaye]

[quote="pad125"]I’m not panicking guys, in fact my panic is over. Engine out and cleaned so I’m done! I do drive a lot in town, London to be exact which as we all know is slowest traffic cycle in the country. But what are we saying here, “the cars not fit too be driven in town“!!!! I’d like to see that on the next RS sales brochure. And as for driving it like I stole it, believe me, I’m no driving Ms Daisy! But I don’t think “I was only keeping my engine cleanâ€

[pad125]

Sort of related.....
Whenthe first Scoobie turbos appeared, prior to buying a two year old example, I asked the mechanic about any faults. He replied that a few where being brought back with lack of power. Asked what they didto fix the problem - replied, take them out for a very spirited drive, cleans all the internals (albiet and turbo vanes). So maybe the hole carbon crap is very relavent to where / how thecar spends its life. Town driving for any performance car isn't great.

I agree totally but you won't get Audi to admit that one of their performance cars can not be driven around town. I think it was MAC who said to me that he took his car for MOT and it just failed so he took the car back, got up at 5am the next morning and thrashed it to within an inch of its life. A couple of hours later and a tank of fuel, he took it back to the garage and it passed. He also noted the small round black balls of s**t all over the rear end.

[aidanjaye]

Sort of related.....
Whenthe first Scoobie turbos appeared, prior to buying a two year old example, I asked the mechanic about any faults. He replied that a few where being brought back with lack of power. Asked what they didto fix the problem - replied, take them out for a very spirited drive, cleans all the internals (albiet and turbo vanes). So maybe the hole carbon crap is very relavent to where / how thecar spends its life. Town driving for any performance car isn't great.

I agree totally but you won't get Audi to admit that one of their performance cars can not be driven around town. I think it was MAC who said to me that he took his car for MOT and it just failed so he took the car back, got up at 5am the next morning and thrashed it to within an inch of its life. A couple of hours later and a tank of fuel, he took it back to the garage and it passed. He also noted the small round black balls of s**t all over the rear end.

Sorry officers, was thrashing the car to within an inch of its life for emission purposes.......worth a try?

[pad125]

Definitely. Picking you’re time and place is key but I think you have to blow out the cobwebs as it were if you’re keep you motor under the dreaded emissions limit

[madgreek]

Check this recent victim of massive buildup.

http://forums.quattroworld.com/rs4b7/msgs/52391.phtml

I notice Audi paid for this one under warranty

He also got 42 HP back after the cleaning! Damn

http://forums.quattroworld.com/rs4b7/msgs/52722.phtml

[P_G]

That may well be but it's a false economy because as everyone acknowledges CB will happen and rated power isn't based on an engine whose internals are clean enough to eat my dinner off.

So anywhere between GBP 600-1000 to get somewhere between 20 and 40 hp for 3-6 months. As I have said beofre, if you have the money spare to do that good luck to you. Even better if you get Audi to do it for you FOC but in the UK that is few and far between even on warrantied cars.

The ultimate point I was trying to make when testing my car against pad125's car after it had been cleaned is not that CB doesn't exist but it is very much dependent on how the cars are driven and the difference in real world terms in peformance is minimal, especially given his car is a saloon and mine is an Avant. I know mine was near emmissions limit last time but took it out like mac and gave it a thrashing and sure enough was a good bit lower.

The other point pad125 once made is that it is not normally CB itself that causes the issue, it is excessive CB which is exacerbated by another factor / fault in the engine. Valve seals not warming up properly during warm up, overfueling / rich mixture / contaminated oil are all factors that have been mentioned at the same time in CB for the cases where people have had their engines cleaned so what's to say they caused excessive CB rather than CB causing them.