Carbon Cleaning
 

A sponsored post popped up in my Facebook feed the other day and it got me thinking.
It was from Doctor Carbon and I popped over to their webpage to have a look and so see what the cost was and the "BEFEFITS" (how they haven't spotted that spelling clanger on their homepage is beyond me :ROFL:).

Anyway, for £75 I thought it might be worth a punt.
When Big Red was down with MJ last year, so much work was invested in her (the car) but the combustion bits were left as they were as there appeared to be no issues.
Well, there still don't appear to be any issues with the internals except for an engine management light that I've not looked at with VCDS yet (but will soon), but as the car is fast approaching 150k miles, I thought this type of treatment would be beneficial.

So I thought I'd ask for some opinions from those that know more than me.
Anybody used this type of service with good or bad results?
Can the high temperatures caused by the pyrolysis potentially cause other issues?
If it ain't broke, don't fix it?
Is it just the motoring equivalent of snake-oil?

Edit: I remembered Edd China doing this on Youtube and have just Googled to see that my local garage offers this Terraclean service so I'll check out their prices if someone doesn't tell me of some disaster stories around this.

Someone more knowledgeable will be along soon, I'll chip in in the meantime :)
Petrol D2s have the good old injector in manifold system, meaning the injector nicely sprays the tops of the valves all the time. Make sure you do WOT now and then so the injectors do a full blast of fuel over the valves.
For this reason I really doubt D2s have much carbon deposits.

Certainly I doubt they have the troublesome deposits on top of the valve which some new FSI engines suffer from. This is the problem type deposit because it can cause problems with valve seating and reduce air intake volume?
FSI injectors are inside the cylinder so never spray the tops of the valves.

So my guess is, total waste of time and money on a D2
Unless it was run on cheap/bad fuel for a long time, and used non-synthetic oil.

Its total snake oil, particularly on engines like ours.

The Terraclean stuff does nothing that petrol don't already do every time you run the engine, especially with the ethanol content in modern fuels. The inside of the fuel system - injectors, fuel rail etc are all spotless, kept so by nice filtered fuel, and because our engines use port injection, the fuel spray keeps the ports nice and clean so there's nothing for Terraclean to do anyway. Your engine's ports were perfect btw.

The only places that really get dirty in these engines are the throttle body (which I cleaned) and the crankcase breather system (which I replaced). Terraclean couldn't do anything with those because they're all upstream of the injectors.

Carbon cleaning does apply to direct-injection engines though (petrol and diesel), especially those with exhaust gas recirculation (egr). The oily vapours from the crankcase mix with the hot soot in the recirculated exhaust gas to make horrid sticky tar which settles on everything. As there is no fuel spray in the ports (since it's directly in to the cylinder) the tar builds up until the engine can barely breathe. Its a common problem on all the FSI and TDI engines, especially the D3 S8 and S/RS4. I've seen TDIs with the inlet so clogged there's barely space for a finger in there! The only way to clean that is mechanically - get in there with tools and dig it out. There's no chemical treatment that's safe to put in an engine which can clean that muck.

You're better off spending your £75 on a tank of Tesco Momentum or Shell V-Power and going for a thrash +++

Edit - I spent far too long writing that :D Good point about dino oil Goran. That killed a lot of early 20V engines.

I've seen a few companies offering this. Terraclean is a different system, I believe this version cleans via the intake manifold although I'm sure someone will correct me.

The Doctor Carbon 'how it works' explanation is complete gibberish. They claim that putting hydrogen in to the inlet manifold increases combustion temperature and burns off the carbon. How does combustion in the cylinder clean carbon from the inlet ports? http://www.corradov8.com/pics/screwy.gif

They're essentially charging you to electrolyse some water and feed the gas in to your engine. Its like homeopathy for cars :ROFL:

I pm'd MikkiJayne about carbon cleaning and i take her word for it +++

Great explantation MJ. Snake oil it is!

Pretty much what I think as well.

Most cars does not need it and if it does need there is no way it can clean 15 years of buildup in 15 minutes. I run Shell V Power and couple of weeks before MOT I add 0.5l of toluene (toluol) to half tank of petrol, you can get 5l for £20 so only £2/year expense for 0.5l. It's good as solvent and safe to use with high octane number, there was era in F1 when they were running cars on 100% toluol. Emissions have always been very good at MOT's and when I took heads off engine it was surprisingly clean even in combustion chamber.

Well, MJ you effectively removed the carbon from Doctor Carbon. +++
What I liked about the website is the "useful" information about hydrogen and its place in our universe :rolleyes: but a total lack of evidence about the results process (apart from unsubstantiated client comments) and a "Before and after" picture of an inlet port. And, as you pointed out, unless the "pyrolytic" reaction is taking place in the inlet manifold :eek: then it is hard to see how this process cleans that area.

Thanks MJ (and others).

You don't get much of a better answer than that.
I feel well and truly schooled. In a good way.
That's money well saved that can be reinvested in a round of drinks at the annual meet. +++