Recently I've noticed a problem when my car sits for a while, at least a few hours, and I go to leave under full throttle the RPMS get to around 3000 RPM and then the power seems to cut off. It's like this for about a mile of driving then everything goes back to normal with no issues. I've got the RMS tune, but even my girlfriends 2011 stock Cooper S had this happen as well. She had it happen first, I thought it was bad gas maybe, but I've been filling up almost exclusively with Shell 93 octane for the past few months. I"ve got 43,000 miles on my 2010 S now. Not sure if it's just the computers waiting for my engine to warm up properly first or what. Don't think it's the tune since it happened to my girlfriends stock S and she has around 33,000 miles on hers.

 

Well the dealer has trouble shot it and they think it's due to carbon buildup. Problem is, there is no check engine lights. They are now waiting to see if Mini will authorize a cleaning under warranty. They contacted them yesterday at 6pm and have had no response so far, bummer. Wonder how much it'll cost if they don't. And or if this is the problem. I was wondering about the fuel pump since I've heard they can go bad, but don't know the symptoms besides car on road dead.

 

bought my 08 s this past sunday ..next morning went to start it and it just shut off did this twice...then had shitty idle the third try.. only did it when it sat for awhile and not everytime....

turned out to be the hpfp they told me it was a known issue and replaced by mini for free

 

My car has never shut off so far. I was thinking it was the fuel pump as well, but we will see. Never did get a response from Mini Friday or Saturday so waiting hopefully on monday the dealer will get word to go ahead and clean the valves and we will see if this fixes this. Next up I'd assume would be the fuel pump. Also, FYI, the plugs were just changed by the dealer about 2 months ago. Again, it only seems to do this loss of power when the car sits for a few hours or so.

 

Is it ok after it warms up?
Computer might be delaying full power till the motor is warm...bmw's have done this for years...maybe the software was updated?

 

Yes it's fine and pulls strong after about 1 or 2 miles of driving. Just never noticed it before. Had the car sit for about 1.5 hours, and same thing, loss of power after takeoff, but after 1 mile or so, all fine and dandy.

 

My suggestion....
If you can get a free carbon cleaning...go for it....you will need it someday.
heck...let them play the warrenty game....

 

If dealer is going to do their 3-step carbon cleaning that's not going to remove the carbon buildup on the back of your intake valves because the carbon buildup on your valves is caused by the PCV system, the PCV system removes oil vapor into the combustion chamber coating your valves with carbon deposits! Direct inject engines do not inject fuel behind the valves, but directly into the combustion chamber.

You want the walnut blasting to clean the back of the intake valves!

 

I don't know which cleaning they are asking for from the manufacturer, I'd assume the walnut blast. I would assume they know about the carbon build up from the current direct injection set up. I was wondering how much that would cost if I wanted them to do it without authorization from mini. Any ideas? I think their labor rate is $115 hour.

 

Don't assume anything if the money is coming out of your pocket, walnut blasting is the only way to effectively clean the intake valves.

 

OK, I love my dealership, FLOW Mini in Winston Salem NC. Not only did they do the walnut blasting of my valves under warranty, they even called me to make sure it was OK to reflash my ECU because they knew I had an RMW tune! What service. The new software is supposed to address the carbon build up or at least limit it. We'll see. I called Jan at RMW and he said it would be fine, he'd just reprogram some things and since I have the DIMM sport programmer, no worries there. Dan, from the former grassroots garage, told me the valves were bad, but not as worse as he has seen. His suggestion is drive like heck to help keep them clean. I already do that, I'll just need to add more track days at either VIR or CMP in South Carolina!

 

Since carbon cleaning helped....
I would STRONGLY suggest a catch-can.
Mounted in a cool place, it will allow vapors to condense, and catch them....might lengthen the timetill the next requred cleaning!! There are a,few good ones....but imo, mounting location...a cool spot, is most important.

 

MINI ECU holds boost back until water temp gets to about 165F-170F. As for carbon buildup.... SEA FOAM!!!!!!!!!!