If you MIni has been diagnosed with a carbon buildup problem in the intake and required cleaning please post your mileage, model and resolution - dealer serviced at Cost, or no charge. Let's get a count going and number every post.

 

81K 2007 MCS. Nothing done, not paying $600 for a cleaning until I can run water/met. Currently have a oil catch can. Oil consumption is noticably starting to go up. Also I have the pass PCV blocked off.

 

84K miles/ 07 S
dealer wants $ 600 to sandblast with "walnut" shells and clean injectors

 

'09 MCSa currently with 23K.

Had a check engine light come on at around 10K that the dealer diagnosed as a carbon buildup and cleaned up at no charge under warranty. No issues since then (knock on wood).

 

Only 10k - Wow. Mostly city or Hwy mileage ? What type of gas do you use, name brand ? What did the dealer say ? Thanks for your post.

 

I was surprised it happened so early. The car was bought brand new.

If I remember correctly the fault code was for a cylinder misfire which they told me was due to the carbon buildup. I'd have to dig out the dealer work order for the details. But it was cleaned and covered under warranty.

I fill up at pretty much the same local Shell station with 93 and it was mainly mixed city/highway driving.

Haven't had any issues since, but I am considering the catch can sometime in the near future.

 

50+K
2010 MCS
engine warning light came on

garage where my friend worked cleaned it up (chemically?) after dealership nearby refused to waive walnut treatment charge

have traded this car in since (after $300 repairs)

packimocity

 

108,000 miles, 2008 MCS. Cost of the walnut shells only - dealer comp'ed me the labor since I was having other major repairs done.

 

2008 MCS cleaned at ~28k miles - No charge as it was done under warranty. At 60k now and expecting that it will likely need it again in the not too distant future.

 

Bought my 2011 MCS on April 30, 2011. Carbon build-up diagnosed around 26,000 miles on May 24, 2012. Service was covered under warranty. I was told not to use cheap gas (I only ever put in 93) and was told to drive it hard (oh believe me I do) and to use fuel injection cleaner every 3,000 miles (why didn't you tell me that when I bought the car?)

Why is this a problem for my MINI but not any of the other MINI owners I'm friends with?

One week after the first service, the check engine light came on and the thermostat needed replacing. A week after that, the check engine light came on again... I don't know what's going on with it yet -- it's at the dealer and I'm stuck in a rental...

Update - I've been told they're now replacing spark plugs and coils...

 

2007 Cooper S, 90k miles. Burnt exhaust valve, lost all compression on cyl #1 (last year). Fully off warranty. Finally pulled head last weekend:





After cleaning up with soda blaster

 

Do you have a write up of pulling the head off? And what did you clean everything up with?

 

karl, thanks for posting those pictures. Excellent job of showing the problem and how things are supposed to look. +1 to what Porthos suggested - a write-up with details would be an excellent addition.

 

I own a soda blaster (medium grade medium), which is generally safe to use around engine internals. It made quick work of cleaning the intake valves and the ports. The exhaust valves were completely resistant to soda blasting on backs and faces. For them I used a 3M wheel on a die grinder to carefully polish the backs and the face outer ring and a miniature cutting wafer on a dremel to meticulously polish the dish on the face. Those last two methods will cut/deform the steel, so you need to keep them away from the stem section that runs the guide, and of course from the the section of the valve where the angles are cut (edges). I used valve grinding compound and a traditional hand grinding tool to renew the seat to valve interface.
http://www.harborfreight.com/15-lb-p...ter-66742.html
http://www.harborfreight.com/50-lbs-...dia-65929.html
http://www.pepboys.com/product/details/9873887/800/

As for a writeup for pulling the head, I'll leave that to someone who is good at it with good experience. It was not a pretty sight, and I'm only 1/3 of the way done the job as I have to pull timing chain, and get it all back together and running.

 

27K on a 2009 JCW with a BSH OCC no carbon build up

 

07 MCSa 40K miles Cleaned by the dealership. They mistakenly told my wife it was covered under her maintenance plan so they ate the cost.

 

Thats the worse I've ever seen an intake system clogged with oil/carbon in 22 years of working on and building engines...

 

That is insane build up.

I am almost thinking a full, head-off cleaning like you've done is a good idea maybe as a 100k mile maintenance item....

 

If you did it yourself sure but, for a mechanic to do it especially if the dealership does it you are talking serious money.

 

09 MCS with 49800 miles. SInce I was coming to the end of the warranty I brought it in for the water pump recall and I complained of "lack of pep" knowing full well what the issue was. Dealer did a full diagnostic found a hairline crack in my valve cover, and a small leak in the turbo oil feed and misfires on the cylinders. Found it to be excessive carbon buildup and did the walnut blasting. Dealer covered everything under warranty. Drives like a brand new car.

 

'10 MCS with 40k. Being done right now.

 

Please keep the posts coming related to Carbon buildup problems. Thanks !!!

 

It seems the carbon build up occurs in the S-models.

 

Indeed, you seem spot on !!! Keep the posts coming.

 

I have concerns of carbon buildup in my '09 Clubman S. I bought the car used with 17.7k miles on it and I drive a lot for work. In 6 months Im up to 28k miles. I only use 93 octane from BP or Sunoco but I fear the previous owner used less than excellent gas. How can I approach my service department with my concern in hopes of getting them to clean my carbon if needed? I need to get an oil change soon so I'd like to deal with it at the same time.