Carbon clean with DIY walnut shell blaster

[Stevec33]

Great thread, certainly an interesting read. Did you notice much performance difference after doing the clean?

[TonyHayers]

Great thread, certainly an interesting read. Did you notice much performance difference after doing the clean?

Seemed to "breathe" a bit easier and rev smoother, but was really a maintenance job and an excuse to try something that I'd not seen anyone doing on RS4s.

I think it's worth doing if you're planning mods - having the intake valves breathing nicely certainly won't do any harm. It's also a fantastic way to get to know these engines (since you have to move so much stuff to get the damn manifold off!).

[RIV]

Haha, come on Silas mate, get it together.

Cars long gone, no one wants the manifold

[ferchizzle]

Thank you for sharing your methods w the members. It is by far the most efficient and thorough DIY carbon cleaning that I have seen.

Do you have the dimensions or a CAD file of the wooden template (that you used to fit over the cylinder heads) to share so I can make my own?

Thanks!

Best,

Kane

Ok, here's some more photos as promised.

To help provide a good seal and mask off the area, I lined each port with gaffer tape...



Then, placed the adapter "plate" over the port with vacuum pipe attached...



Underside of adapter, showing wood insert shaped to fit port. Bit worse for wear after a pummelling from walnut and carbon...



Top of adapter plate. The black pipe bit is a 22mm plastic plumbing pipe insert with a bit of gaffer tape to make it a tight fit with vacuum pipe...



Blaster fits through other hole in adapter plate and is heavily countersunk so the blaster can be rotated and "wiggled"...



Appliance hose fit nicely over the dyson handle attachment. I should mention that there is a bit of a drawback to this approach, in that it puts a lot of strain on the vacuum motor and it heats up a lot. I triggered the thermal cutout a few times which means that the vacuum was out of action for around an hour until it cooled down. To get round this, I just ran it for 30 seconds at a time, then turn off vacuum and inspect port etc. I tried with just having a smaller hose inserted a foot or so up the dyson hose, but then you don't have the suction power you need to keep up with the blaster...



Makeshift hopper...



In progress...



Whilst everything was stripped, I thought I'd give the filthy valve covers a good clean...

[TonyHayers]

Thank you for sharing your methods w the members. It is by far the most efficient and thorough DIY carbon cleaning that I have seen.

Do you have the dimensions or a CAD file of the wooden template (that you used to fit over the cylinder heads) to share so I can make my own?

Thanks!

Best,

Kane

Um, no. I drew the shape from the manifold gasket. It's really not complicated!

[ferchizzle]

Thank you!

[Covkiller]

Just had a quick carbon clean at MRC whilst they changed my knock sensors. I'll be using your link to clean my valves on my own in the future.
In all approximately how long did it take you to clean you valves form start to finish?
A great posting, well done.

[TonyHayers]

Just had a quick carbon clean at MRC whilst they changed my knock sensors. I'll be using your link to clean my valves on my own in the future.
In all approximately how long did it take you to clean you valves form start to finish?
A great posting, well done.

I think I prob spent about two long days on it altogether. The actual cleaning process isn't too bad at all, in fact it's quite cathartic - it's getting the manifold off that takes ages.

[sakimano]

Just had a quick carbon clean at MRC whilst they changed my knock sensors. I'll be using your link to clean my valves on my own in the future.
In all approximately how long did it take you to clean you valves form start to finish?
A great posting, well done.

I think I prob spent about two long days on it altogether. The actual cleaning process isn't too bad at all, in fact it's quite cathartic - it's getting the manifold off that takes ages.

+1

But the second time and thereafter it is much easier. A friend can have it off in 45 minutes. He's a mechanic himself though but he shared your sentiment.

Most guys here use oven cleaner to deal with the carbon itself. Turns it to soft sludge you can wipe off

[adsgreen]

Oven cleaner? Sodium hydroxide? On aluminium?!?
It's s powerful base that'll eat aluminium alive.
Not sure how it'll react with valve stem seals either.

[Youngben]

Cleaners have always worried me because of the stem seals and what it will to to the valve seats. You could be causing more harm than good.

This dry blasting method is by far the best idea i have seen to date for tackling the problem.

[dust1961]

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.

[boombastik]

Just had a read thru this thread and can safely say some excellent work & advice is found within, i'll certainly be referring to this when its time to decoke

[sakimano]

Cleaners have always worried me because of the stem seals and what it will to to the valve seats. You could be causing more harm than good.

This dry blasting method is by far the best idea i have seen to date for tackling the problem.

audi used to use the media blast but stopped ABRUPTLY a few years back. Wonder why.

[barryrs]

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.