My 08 MCS had carbon cleaning about 25k miles ago, just before I bought it. ONe of the first things that I did was put an OCC on it. I just pulled the intake and peeked inside the ports. The ports were clean, with no buildup in the entrance or throat. I did see various degrees of buildup on the back of the valves, but no restriction like I saw on other pictures with crusty ports surrounding the valves. I realize that the crap on the back of the valves will affect flow.

At what point should I need cleaning again? Sorry, I didn't think to take pictures.

Mike

 

I waited till 93k to do the first cleaning. Hmm I would say it would be a good idea every 60 to 70k miles.

 

The Mini maintance schedual list it as a service at the 60k to 65k mile service. I think there is also a time component in years but most hit the mileage first.

If you have a catch can and the throttle body PCV hose also capped or diverted the above interval will have no bearing. as the PCV will not be dumping oil into the intake at the same rate as a stock system. I do not know personal any one that has had a cleaning done after to know what mileage that it needed to be done at.

I would still have it done at the 60k to 65k just to keep the motor happy and that is about when the timing guides and tensioners are getting iffy on the motors. or at least that is what i have read. I just picked up mine not to long ago and got a free chain and cleaning because dealer (not a Mini) put the wrong regular gas and had to send to Mini to correct the issue for me.

 

I just did mine over the weekend. Mine is a 09 with 35k miles (OCC installed at 25k). Although mine wasn't as bad as some on here it was still significant enough to make a noticeable difference in performance after it was complete.

Granted my before picture was taken of the screen of my Whistler inspection camera you can still see there is significant buildup given the poor picture quality.

 

I would say that if you can see visible chunks starting to occur time to clean