Carbon clean with DIY walnut shell blaster

[TonyHayers]

I have just competed de-coke with my DIY walnut blast and vacuum. Excellent results can give advice and pictures of the setup if anyone is interested. Also did away with the inlet flaps and took the slack out of the linkage for the positioner feedback. Not recommended for a novice but anyone used to doing their own work it can be a big saving.

Nice one

[PetrolDave]

BMW have developed a specific walnut shell blasting tool to address this on the turbo mini's and even sent out a DIY guide adapter head in the meantime for the N73 engine.

Which goes to prove what many have been saying on here for a long time - carbon build-up is NOT a problem that only affects the RS4, but to a lesser or greater extent is something that affects all DI engines.

[sakimano]

I didnt think Audi did this in house so the whole head would need to be removed; therefore the cost was substantially higher.

BMW have developed a specific walnut shell blasting tool to address this on the turbo mini's and even sent out a DIY guide adapter head in the meantime for the N73 engine.

They actually did use media blast. In North America at least, but procedures are generally handed down from Germany.

[TonyHayers]

Just worth noting that this thread wasn't just any "media blasting" (e.g plastic beads, sand, metal shots etc). We're talking about crushed walnut shells, basically granular hard wood. Personally, I wouldn't use anything else. Two main points: 1) it's much softer than the metal we're blasting, but harder than the carbon deposits (especially once they've been softened with carb cleaner) and 2) it's combustible - leftovers get burnt up immediately.

[sakimano]

Yes, it's almost always walnut shells on engines. That's what Audi used over here. BMW too.

[TonyHayers]

Yeah, BMW over here is where I got the idea from tbh.

[adsgreen]

I do like the idea of the dry ice blasting - much less mess and nothing to combust at all. Just expensive.

[GlenRS]

Well I gave this a go yesterday, and my god what a job.

Manifold off and on is a bit of a pig but we had that off in about an hour hand a half and back on in about an hour. I didnt soak the ports for an hour, but did for a while.

The entire job start to finish including removing the manifold and refitting took 12hours. My car went well as it was and when I got the mani off I didnt think it looked too bad in the ports, but it has def made a big difference.

Cheers for the heads up on the process as it def looked nice and clean when I had finished.

[TonyHayers]

Well I gave this a go yesterday, and my god what a job.

Manifold off and on is a bit of a pig but we had that off in about an hour hand a half and back on in about an hour. I didnt soak the ports for an hour, but did for a while.

The entire job start to finish including removing the manifold and refitting took 12hours. My car went well as it was and when I got the mani off I didnt think it looked too bad in the ports, but it has def made a big difference.

Cheers for the heads up on the process as it def looked nice and clean when I had finished.

Yeah, I wonder if I did soak mine for an hour -does seem too long tbh

Did you get any photos? if so, you know the drill...

[GlenRS]

Im afraid I didnt, didnt really get the time to stop and think about taking them as it took long enough as it was, but they were much like yours.

Made use of a fine nozzled air blaster which was really helpful for blowing out some debris and also good at generally dislodging big bits before the walnut shells. Also came in handy for cleaning up the edge of where the valve seat sits when I had finished balsting with the shells.

Can certainly say its not something I want to do again in a hurry, might look into water meth to keep it clean.

[Patgas1]

I too will be looking to do this soon
List of gaskets ect would be really handy cheers

[TonyHayers]

I too will be looking to do this soon
List of gaskets ect would be really handy cheers

I think I listed everything I used except a pair of intake gaskets. Not sure I included them, but everything else is listed earlier in the thread.

[docurley]

Before I forget, thought worth mentioning couple other parts/tools that I bought for this job...

1) Wooden scraper/pick tools
eBay: http://www.ebay.co.uk/itm/320868956691



2) Super low profile 1/4 ratchet driver (for bolts on back of Oil separator/breather)
eBay: http://www.ebay.co.uk/itm/261208747792



3) 14mm x 17mm Flare Nut Spanner (for fuel rail nuts)
eBay: http://www.ebay.co.uk/itm/280803797152



4) Geniune replacement check valve
eBay: http://www.ebay.co.uk/itm/150995675646



5) Silicon vacuum hose 8mm OD/4mm ID (for relocating above check valve)
eBay: http://www.ebay.co.uk/itm/300691592592

Just buying all the bits for this but a little lost with the pipework for the check valve bit.
So what I need to know is size of the hose (i see 4mm and 8mm listed) do I need and where do you relocate it too?

[TonyHayers]

You need a piece of silicon tubing with 8mm outside diameter and 4mm inside diameter. 1 metre is probably enough, can't quite remember how much I used though.

The check valve as standard is impossible to get to without removing manifold. Somebody on here wisely suggested relocating it while intake manifold is off, so that it can be reached in future without removing intake manifold. Mine is now located underneath the small front carbon cover, where the other vac lines run.

[docurley]

Ok thanks for that.