I'm in the process of cleaning out the carbon buildup on my 2008 MCS with 58k miles(New to me.) I was really shocked to see how much buildup there actually was!
Thanks to the forum, manifold removal was a piece of cake.

 

Which system are you cleaning them with ?

 

Walnut blasting. I already had the air compressor, just picked up some walnut shell media/portable blaster from harbor freight. I purchased the adaptors used from someone on the forum a couple weeks ago.

 

Did you get to do it yet? Any pics?

 

I did finish it on Sunday. Taking the manifold out/reinstalling it was the easiest part of the job. Getting all the carbon build up out was a major pain! I'm not sure if my compressor wasn't strong enough(could only spray for about 40 seconds before it would kick on), or if I should have gone with the coarse walnut shells, but it took HOURS of spraying/scrapping to get it all out.
Driving it this week I've noticed about 5mpg better overall gas mileage(Right at 40mpg now with about 85% highway driving.)

One thing I find weird is my boost pressure seems to be a bit less than before the job, but the car pulls harder? I was seeing 16psi before, and now I'm getting around 14psi.

Here is a pic I took when I was almost done. I found that using the phone/flash was much better for judging my progress than a mirror.

 

Now that you've cleared the carbon deposits... what are you planning to do to keep up with it. Seafoam treatments perhaps? Better fuel? Gas additives? Excellent job by the way!

 

Thanks! I have installed a BH Catch can that will hopefully help. I will look at it again in 10-15k miles and clean if needed. I plan on doing the sea foam thing every couple months, but I don't see how any chemicals could remove what was already built up! I'm not sure if better fuel will help either... Fuel doesn't spray into the manifold or on the back side of the valves.

 

What are the adapters you used?

 

It's a adaptor that goes into the head and hooks up to your vaccum cleaner to suck the walnut shells out as you are spraying them inside. It has a small hole in the center where you can insert your air/walnut gun. There is a thread on the forum where someone built their own, but I got a fair deal on a used tool and went that route.

 

Did you get the portable blaster from Harbor Freight? Was it something like $35-$40?

 

I did. Harbor freight always puts out 20% off coupons as well.
http://www.harborfreight.com/portabl...kit-37025.html

 

Your boost is probably less now because there is less restriction in the intake. Think of it like a hose with a small nozzle versus no nozzle. The water sprays much harder with more pressure with the small one, but running no nozzle lets much more water through per minute. Same thing is going on in your intake.

 

Can we get a pic of that walnut blaster set up?
Might be something i need down the road lol

 

Don't do the can stuff, no point , I had mine since 2k from new, and the passenger port block. Looks the same as yours . Only solution( apart from cleaning ) is VTA and rerout , expansion plug in the intake.

 

I have an '07 MC with the about the same miles (57k), and I'm wondering if the carbon buildup is as bad on the non-S.

 

You need not worry. Your 'Justa' has the N12 engine which is not direct injected, so you will not have the same carbon issue like the 'S' models with the direct injected N14 engines.

 

Cleaned the valves about 4K miles ago. Last week i had to remove the intake manifold to replace the water pipe so I looked inside. Valves looked much like yours. This was 4K miles WITH a BSH catch can! Like WAC said ...the only real solution for these engines is vent-to-atmosphere. I really hate to do it...at least I'll vent through the catch can. I catch a lot of oil/water during the cool months...nothing in the warm ones....just won't condense in the hot can.