Asking this because it seems an attractive option in relation to the performance/economy balance.

Is there any consensus regarding whether VAG sorted out the carbon build up problem by the time the 1.8 TSI engine came out?

Thanks

No direct injection engine has found a way to stop this happening. It's a by product of modern emissions regs.

How does that issue manifest itself into a problem over time?

How does that issue manifest itself into a problem over time?

Not speaking from personal experience as I currently have a 1.9 PD diesel. But my understanding is gradual loss of performance only cured by frequent decokes – The sort of thing your Granddad did on a Saturday afternoon every 10 000 miles on his side valve Ford Prefect. The only problem this is a much trickier proposition on a modern engine.

So if I run the car for 20 years it'll be knackered with no real solution at that time?

That's a bit depressing. It was easy chucking a bit of redex in my old carbed golfs to sort that back in the day but you can't use it on injectors. :wonder:

Apparently there is something you can introduce to the air intake that's supposed to remove the carbon build up but I forget the name of it. It might be on here where I read about it. Try doing a search for carbon clean or something similar

Yeah, just been reading about it. It's called Ecotek Powerboost. Seems a bit of a stitch that they recommend you apply it every 12,000 miles though which is probably about every year.

http://www.terraclean.co.uk/

Anything that goes into the fuel system (Terraclean etc) is not going to help though as the fuel does not go through the inlet manifold.

How does that issue manifest itself into a problem over time?

I had a persistent misfire on my 2.0 TFSi. The car would be running fine but under load it would misfire and sound like a bag of spammers, shidder, etc.

First the coil packs were suspected, so various changed. They thought it might be the ECU but before going to that expense wanted to try the cheaper alternative of an injector change. It was upon dismantling to do that when they saw that the intake valves were coked up.

Basically a build up of carbon was preventing the valve from operating. The head had to be removed and remachined by VW and the valves had to be stripped and cleaned etc. total bill was well over £2k and total mileage at that point was about 40k on a car less than four years old. Skoda chipped in £700 IIRC and when I complained they refused to budge. I asked if they thought it was acceptable for an engine to last less than 40k before such major expense and they said nothing lasts forever!

Skoda couldn't offer any advice on how to stop it happening again but following a fair bit of research online I found the problem affects all DInengines and that Porsche and VAG seem to have the most complaints. Best practice appears to be always use super unleaded (I did anyway) and make sure you take the car for an 'Italian tuneup' once a month.

So, poodling around town doing shopping and taking family here and there is a big No No. It needs to be a monthly visit to Germany to see who can drive to the bratwurst stand the fastest!

Pretty much yeh.

Nothing can be done to prevent it on early DI engines but as OctyOGG was saying later DI engines do not suffer from it.

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156,133 miles and counting on my tfsi,just give it some beans every now and then

Nothing can be done to prevent it on early DI engines but as OctyOGG was saying later DI engines do not suffer from it.

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I think you've misread something (or I have). I don't recall anyone saying later DI engines are any less likely to suffer and TBH I don't know any reason why they should be any less likely to suffer......

They had to cut out valve overlap to prevent exhaust gas escaping into the intake which is the cause.

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Anything that goes into the fuel system (Terraclean etc) is not going to help though as the fuel does not go through the inlet manifold.

It recirculates through the EGR valve as it runs rich.

It recirculates through the EGR valve as it runs rich.

The problem is even Terraclean themselves cannot prove that this is going to work, all it needs is a borescope down the plug hole before and after the treatment, yet they are not prepared to do this.

It does appear to be a great system, but until it has been proven on a DI engine the jury is still out.

Having watched the Terraclean video on their site it worries me when the presenter makes up words (ariphatic or arophatic, invented by mixing aromatic and aliphatic!) and then they lie about what they are running the car on (non-carbon based!). All you need to do is access the MSDS (material safety data sheet) on-line to see it is 60-100% petrol - bog standard fuel. No doubt there are additives and they possibly treat it by magnets or putting a charge through it, hence the nonsense about the -vely charge particles attaching to the +vely charged carbon ??? As for the additives, nothing else is listed on the msds, so that is also a concern that there is nothing else in there warranting a mention. If there was absolute confidence in their product as Gizmo says there would be a visual inspection involved, or before and after pictures on the website.

this guy has the answer - http://www.audiforums.com/forum/off-topic-5/hey-guys-please-help-my-mods-gone-wrong-80267/

Old 'uns are the best.

I doubt anything that mixes with the fuel is gonna clean the intake valves as it does not wash over the valves as it does in an indirect. It does recirculate through the EGR but it is mixed with exhaust gas and only breifly contacts the intake valve, maybe if you ran it with terraclean 24/7 it might make a difference. The only sure fix is what mr awol says, rebuild the head.

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this guy has the answer - http://www.audiforums.com/forum/off-topic-5/hey-guys-please-help-my-mods-gone-wrong-80267/

Old 'uns are the best.

as somebody already said, that has to be one of the most stupid posts I have ever read!

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