This is a How-To on Removing the Carbon Build-up, the right way.

I couldn't take it anymore with the decreased performance. My car has 60K miles on it (I bought it with 50K a year ago) and I don't think the carbon build-up has ever been removed properly. The throttle was sticking, the performance was down and it just felt like the car was struggling.
I know there's a lot of people that swear by the Seafoam method, but I've run 2 bottles through my car in 4K miles and it's done nothing. I also got taken for $250 for a dealer method (while the car was in for other service) that was only a temporary fix (a few days and a warm fuzzy feeling).

So, I decided to tackle cleaning the intake ports/valves manually myself. I wasn't going to pay the dealership $$$$ without having some way of verifying it was done right and I just don't trust them. It's my car, if I want it to last, it's my responsibility.

After reading a few posts on cleaning the valves, I didn't see where anyone had done a full writeup on the procedure. I figured I would jump in and do the writeup, so others can do the maintenance, regain the lost performance and learn a thing or two about our cars.

The result? Amazing! I feel like my car runs brand new. The performance is back, the throttle works perfectly and it runs much smoother. I put in the BSH Oil Catch Can after I cleaned it which will definitely help reduce the buildup in the future.

Believe me when I tell you, you can do it. It's not major surgery and only takes a Saturday. I tried to lay out the steps as detailed as possible, for the inexperienced.

If you have any questions, shoot me a PM. Enjoy!

 

Excellent manual. Thanks a lot! I will try on my Peugeot 308 which shares the same engine with R56, no matter some minor differences in air piping. I also suggest using Shumma engine conditioner, an original fluid from Mitsubishi. It was developed specifically to clean valve ports on GDi engines. It makes foam and dissolves gunk and tar without leaking and evaporating like carb cleaner.

 

Some small things I've noticed about the guide. You forgot to mention the 10mm bolt that holds the intake manifold inside the engine bay. Also, the screws on the throttle body are T30.

 

Texasmontego....THANK YOU SO MUCH. This had to have taken you a LOT of time to write up such a detailed guide. The pictures.....Its amazing. The best I've ever seen. Whats really cool is, 10 years from now, some person you will never meet will be in a REAL jam, and will be searching the internet and come across this guide you wrote and it will save their tail. I've already saved it to my hard drive, knowing I will need it someday. Thanks again, and well done.

 

any chance that the carbon buildup might be responsible for AutoStartStop malfunction (not working to be frank) or loss of power/turbo boost over 4000rpm?

 

I have been experiencing low power and difficult cold starts so i have to Thank you for this excellent "how to"
I used your write-up to perform this procedure on my 07' S just last week and it really made a difference in power and gas milage!! the difficult cold starts remain so it's at the dealer, my guess is the fuel pump is failing, we will se what the dealer says.
I have a small head and so I didn't need a mirror to see what I was doing.
Surprisingly, you did neglect to mention the nut that must be removed from the bottom of the intake as it was the most difficult thing about this evolution due to its near inaccessability as well as being blocked from easy view by the intake.
I only found it after groaping around down there with my greasy hands to try to find out why the intake wouldn't come out.

 

thanks... dealer is charging $500 to do the walnut cleaning... I can't accept that kind of cost in good conscience.

 

I haven't done this yet, but your write up certainly lends courage to attempt it. You should consider a side job in technical writing.
Christmas Eve would be so much happier if others had such skill. Santa has wall tested many a toy with "some assembly required".

 

Hi there,

I'm new to the forum. But I have dealt with carbon on valves and ports before and have lots of experience.

Can you describe what builds up on the valves? When I have removed carbon from the back side of valves in the past the carbon was very hard and baked on; it required a wire bit on a drill or chipping away.

For something to be removed with a toothbrush it must be very soft.

Thanks

Chris

 

Wonderful manual. Wish there were more of these. With that said:

I've never done this fix, and have hardly worked on my MINI, but as a mechanic, I really dislike step #12. There must be a better way. I'm not sure, but maybe something like: Putting the car in gear (1st?), jack up the front, then spinning the front wheel manually? I'm also a guy who refuses to do maintenance with anyone else.