B8 RS4 and engine carbon issues

[Gizmo68]

I would like to think that it has been reduced yes, they are never IMO going to eliminate it whilst the current EGR valves are used.

Even those running catch tanks etc still seem to suffer just as bad.

Ideally we need a guinea pig to remove the inlet manifold, take some photo’s, rebuilt it, run the Terraclean system through it then remove the inlet manifold again and take new photo’s to see if there is any improvement, or whether the only answer is to physically clean the carbon out.
Obviously the guinea pig also needs to be totally independent of Terraclean.

[TonyHayers]

That will only tell you half the story though as you will not see behind the valves and in the inlet port, where I gather the carbon build up will be the worst?

Yeah, but I'm interested to know if it actually cleans the combustion chamber - if it doesn't clean that it's unlikely to touch the inlet port.

I think adsgreen has an interesting point that if the carbon deposits have made their way to the inlet port as a result of combustion, then surely the molecules from the terraclean product could also reach that carbon as a result of the same combustion? I suppose the question is how long you'd have to run this process to affect that build-up which has occurred during thousands of hours of the engine running normally.

I don't foresee that this will make anything like as much difference as a manual head-off decoke, but I reckon it's prob worth a shot to see what it can do.

[Gizmo68]

Well if you believe the hype about the product then there is no reason why the combustion chamber will not be cleaned.
Personally I think the inlet ports etc are coked up due to the exhaust gasses being recycled through the EGR. and back into the inlet.

ATEOTD Terraclean claim it will clean the whole system right through to the exhaust tail pipe.

[adsgreen]

That will only tell you half the story though as you will not see behind the valves and in the inlet port, where I gather the carbon build up will be the worst?

Yeah, but I'm interested to know if it actually cleans the combustion chamber - if it doesn't clean that it's unlikely to touch the inlet port.

I think adsgreen has an interesting point that if the carbon deposits have made their way to the inlet port as a result of combustion, then surely the molecules from the terraclean product could also reach that carbon as a result of the same combustion? I suppose the question is how long you'd have to run this process to affect that build-up which has occurred during thousands of hours of the engine running normally.

I don't foresee that this will make anything like as much difference as a manual head-off decoke, but I reckon it's prob worth a shot to see what it can do.

Misunderstood me - if you boroscope a cylinder with an open intake valve you get a great shot of the back of the valve. A before and after terra clena on that will give a good indicator for the rest of the system.

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This is a great example of what I mean.
http://forum.rs246.com/viewtopic.php?f= ... th#p546640

Hell of a lot cheaper than manifold off and would give a good benchmark.

[TonyHayers]

Well if you think about it like this...
If the intake deposits are a by product of combustion finding its way in.
So in theory any product that can survive combustion will also get dumped into the intake by the same process.

What did you mean by this then??

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Quoted wrong post

[don]

This is a great example of what I mean.
http://forum.rs246.com/viewtopic.php?f= ... th#p546640

Hell of a lot cheaper than manifold off and would give a good benchmark.

Wow that is an amazing effect! The first I have heard of it but a simple solution of injecting a water/methanol mix in the intake. I thought that was just something that people used for hooning or at the drag races. Alcohol and water are really good solvents so no reason why it wouldn't work and looks like it does. Though some (Audi) may not like the idea of injecting methanol and water into the engine so warranties may be concern though as I understand it if done properly there is no harm to the engine. It's also not quite clear what ratio of water to methanol he used but for cleaning purposes it presumably does not have to be as high as the 50:50 mix at the races.

before:


after:

[TonyHayers]

I think he had a proper carbon clean first and then the water meth injection system fitted. He says in that post that the mix is effectively 50/50.

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Yes but the second picture is 18,000 miles ater that.

[don]

Ok so we don't really know for sure if it was the carbon clean or wather/methanol doing the job? Still it is a similar concept to the Toyota solution, something inevitably has to be injected into the inlet manifold regularly to keep the inlet valve and seat clean.

Edit: Ok so there has not been a build up for 18,000 miles, that is a good sign! I also wonder how much better the engine pulls with the methanol injection added?

[TonyHayers]

He did a carbon clean to get a clean slate (so to speak) and the water/meth has kept it really clean since.

[Gizmo68]

[quote=“adsgreen”]Misunderstood we…[/quote]

Ah thanks, yes I see where you are coming from now, that would be good enough for me and the extra cost / labour would be negligible

[don]

I hate to be a dooms day but what is the risk of these systems malfunctioning and injecting too much water into the engine? Which of course could be fatal.

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I hate to be a dooms day but what is the risk of these systems malfunctioning and injecting too much water into the engine? Which of course could be fatal.

It's a tiny amount and use similar technology to fuel injectors... Don't often hear of them injecting too much fuel.
It's also at the maf of the intake and this is a long way from the cylinders. If it were to dump a litre in then alot of it would get trapped in the intake manifold as the cylinder trumpets curve over and face down. Not great but doubtful completely fatal