MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: svvg on September 03, 2019, 03:04:00 PM

Title: Carbon cleaning from intake (walnut blasting etc.)
Post by: svvg on September 03, 2019, 03:04:00 PM
I've seen a couple of interesting, albeit slightly older threads on the benefits of intake cleaning on the FSI engines, including a really detailed guide on this forum. Is this something worth doing on a 113,000 mile AXX GTI engine? If I do decide to do it, is it worth spending the extra on walnut blasting - or is it not worth the cost over DIYing with carb cleaner and plastic/wooden scrapers (which wouldn't be as thorough as walnut blasting)?

There seems to be some doubt over whether performance is affected on turbo engines, whereas the N/A direct injection engines really seem to benefit (like the RS4s etc.).

Any thoughts?
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: titchy on September 05, 2019, 11:57:12 AM
I have read good things about Terraclean
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: svvg on September 06, 2019, 08:58:39 PM
Terraclean seems attractive as there’s no need to disassemble much - but folk tend to complain that after an initial quick fix, the car returns to the way it was pre-clean. I think for baked-on, coked-up intakes, manual cleaning/blasting media is probably required. I have a new intake gasket and injector seals - so will probably have a go at DIY cleaning with plastic scrapers and carb cleaner. Won’t be as super-clean as walnut blasting - but not sure the difference will be worth the £300-400 cost...
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 06, 2019, 10:41:44 PM
Take it to R-Tech and get it done properly


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Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: bobby_fodge on September 06, 2019, 11:23:31 PM
Take it to R-Tech and get it done properly


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What measurable benefit is seen after having this done?
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: svvg on September 07, 2019, 02:02:48 AM
It can help with emissions if this is an issue - and with a lumpy idle. Depending on how gummed up the inlet is (especially if valves aren’t closing properly) it can also restore lost power - but it depends on the engine/mileage etc - hence was asking whether there’s much of a need on the mkv gti with my sort of mileage (113k) as I’m pretty new to these cars.

On the N/A cars with direct port injection they can lose over 20bhp after 60,000-80,000 miles which can be recovered by cleaning the inlet ports (Audi RS4s etc), but I’m not quite sure what folk reckon on turbo cars. I guess it’ll depend on how restricted/gunked up any given car is - but was interested to see if anyone had any strong views.

On terraclean - I think the jury's still out. Tends to get panned as a very short term/possible placebo on BMW forums for N/A cars - but then they don’t suffer with direct port injection issues in the same way (E46 cars in fairness. I’ve not read up much on the effects in the N52 and newer engines in the E90s...).

Manual scraping or walnut blasting seem to be more realistic in terms of cleaning the ports from baked on carbon and sludge on the fsi engines from what I’ve read - but I’d welcome feedback from those who’ve done one or other and can report their experiences??
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: colesey on September 07, 2019, 05:30:48 AM
SVVG, you ultimately won’t know what is in there until you get the intake manifold off however a bit of googling should confirm that it is likely that your car will have carbon build up.  I am sure you will be able to get most of that off by manual scraping however it does appear to be a laborious and mucky job. In addition to the walnut blasting, RTech also test and service the injectors and this might be where more of the benefits in responsiveness / cold starting / smooth idling / emissions are coming from.

In terms of quantifiable benefits, I am pretty sure that RTech did a before / after cleaning dyno test showing @10% gains in the midrange but clearly this will vary from car to car.
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 07, 2019, 09:18:16 AM
SVVG, you ultimately won’t know what is in there until you get the intake manifold off however a bit of googling should confirm that it is likely that your car will have carbon build up.  I am sure you will be able to get most of that off by manual scraping however it does appear to be a laborious and mucky job. In addition to the walnut blasting, RTech also test and service the injectors and this might be where more of the benefits in responsiveness / cold starting / smooth idling / emissions are coming from.

In terms of quantifiable benefits, I am pretty sure that RTech did a before / after cleaning dyno test showing @10% gains in the midrange but clearly this will vary from car to car.

What he said -  :congrats:
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: svvg on September 07, 2019, 01:49:31 PM
Thanks both - the more I’m reading and hearing from forum members, the more this sounds like the way forward. For me, I think I’ll clean the inlets myself, but send the injectors away for ultrasonic cleaning and flow matching.
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: colesey on September 07, 2019, 04:24:37 PM
When you do the maths - is @£150 for injector service plus xxx for gaskets etc - then £350 for Rtech service doesn’t seem much more. They even do a package complete with custom remap for £650.
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 08, 2019, 10:05:37 PM
When you do the maths - is @£150 for injector service plus xxx for gaskets etc - then £350 for Rtech service doesn’t seem much more. They even do a package complete with custom remap for £650.

What he said


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Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: neilw on September 09, 2019, 06:30:44 PM
When you do the maths - is @£150 for injector service plus xxx for gaskets etc - then £350 for Rtech service doesn’t seem much more. They even do a package complete with custom remap for £650.

Not long until I get the full works! I'll be on here to let everyone know what it's like!
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 09, 2019, 06:54:50 PM
Mines been done, minus the injectors, as I provided new ones for the K04 conversion. Just waiting for milly zorst to be delivered and hopefully go up to collect on Saturday


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Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: muff1991 on September 10, 2019, 10:01:51 AM
Mines been done, minus the injectors, as I provided new ones for the K04 conversion. Just waiting for milly zorst to be delivered and hopefully go up to collect on Saturday


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@ljc19630 (https://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=37183) how's your conversion going? Taking a while isn't it  :thinking:
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 10, 2019, 05:24:24 PM
Ha Ha, yeah its been a while, but I'm in no rush!!! Had an issue with the exhaust as the backbox was restricting flow and not able to maximise power, hence just bought an R32 style non-res Milly system from eBay that a chap had on his GTi which is arriving Thursday to be fitted. Also, Pip called me today to say that my VIS HPFP had failed and they are getting a new one sent out. He's fitted hundreds and its the first to fail so VIS sending via next day delivery - I may get it back Sat, if not early next week  :jumpmove:
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: OllieAKS on September 11, 2019, 11:23:21 AM
Don't even bother with a 'Terraclean' or any other shabby carbon cleaning services that claim they make a difference, because they don't and it's all placebo. They literally do nothing on direct port injection engines.

Get the inlet valves cleaned properly with walnut blasting.
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: ljc19630 on September 11, 2019, 11:34:55 AM
what he said  :congrats: :congrats:
Title: Re: Carbon cleaning from intake (walnut blasting etc.)
Post by: svvg on September 16, 2019, 10:23:57 AM
A little update - thanks for input above.

I stripped the car down over the weekend and cleaned the inlet ports and the flaps on the inlet manifold. Was a mission - only because I really struggled to get the correct combination of ratchets and bits together in order to remove the four throttle body bolts. Took over an hour to remove and another hour to reinstall those four bolts alone! The rest of it was pretty easy.

Inlet ports ranged from a bit gunged-up, to caked, in two to three table spoons worth of carbon/mud. I scrapped them with a screw driver (before anyone goes nuts, I was delicate - minor scratches, if any, in the aluminium head won’t affect anything as it’s supposed to be rough in there and the valves are hardened). I then sprayed CRC GDI valve cleaner directly into the port I was working on (bloody expensive at £38 for 500ml can - but I watched a you tube clip of a guy using it on a bmw 335 - and it looked seriously good) - filling the port completely up - and left for half an hour (rather than spraying into the inlet pipe with the engine on - which is how it is intended to be used....). Gave a scrub with an old toothbrush and then drained with kitchen roll. Scraped the sludge out and then filled a second time and scrubbed with toothbrush. Again drained it out and cleaned with brake cleaner and finally blew it all out with a compressed air can.

All the ports came up really well. I’ll try to post some before and after shots - but pretty consistent with other pics you’ll find on the net. There is residual colouring/varnish - but so thin that it won’t affect anything. The car starts without chugging - and feels a tad keener - although by no means night and day on performance. Chugging and aggressive vibration on start up were my key drivers for doing this - and so far so good.

There is a slight blip/misfire at idle - but I think that was there previously - and a slight flat spot on gradual acceleration - which I hope to remedy with new oil, sparks, coil packs, fuel filter and checking whether the diverter valve has had it - all to be done next weekend...

I had to improvise when installing the teflon injector seals, as I ran out of time on Saturday to go to my local dealership for them to install the teflon seals properly. I’d usually wait it out or buy the correct tool - but had to have the car ready for the nursery run today - used a metal biro tip (the bit which unscrews by the nib of a pen) - as it had a metal cone which perfectly matched the end of the injector - and then chopped the pen lid so the taper was just the same size at the injector diameter (and smoothed the inside out,  as there’s usually a strengthening ridge of plastic) - and used that as a make-shift compression tool. Left it in situe for half an hour over the seal, and it had squeezed it down to size. I did use a small amount of silicone spray on installation (despite all the manuals advising not to lubricate) - as they were a bit proud of the injector, and I didn’t want to risk damaging them - and so far no leaks - but will report back/fess-up if that transpires to have been a mistake...

Will post some pics of the “tools” in case it helps anyone else.

Thanks again for input. Quite straight forward to do, save for access to the throttle body bolts, which were a total bugger. A tiny hand held ratchet with a bit holder worked in the end.

Oh - while I remember - the satan bolt was piss easy. I used a 3/8th M10 triple square/spline bit (as per the bolt....) - but on a long 1/4 inch extension - and the extension is thin enough to slide between the hard pipes which would otherwise block access.

Thanks again for all help/feedback above...!