About a week ago, started my 2012 Countryman (77k miles) after it sat for 24+ hours. Severe stutter and stumbling upon start and the yellow engine light came on for about 3 seconds - going out after it began idling normally and everything seemed fine. Drove the car a few days with no other issues until a couple of days ago, same thing but the engine light stayed on. And again today, the stutter and stumbling lasted for several minutes then drove fine - but the engine light remains on.

I've read several accounts of carbon buildup, are there any other potential issues that I haven't found? FYI, I do mostly highway driving and use Shell (93 octane) Premium almost exclusively. Thanks!!

 

I'm a new MINI owner with the same model but with less miles (8k). When i purchased mine I asked the MINI service manager about gas and he HIGHLY recommended BP. And to prevent carbon build up, he suggested that I run the car empty, fill it up and hit high RPMs while in 1st gear or parked to kind of get rid of some of the carbon build up. (if any) I would suggest changing gas stations...

IDK though. I used to own a 99 Civic full exhaust and engine mods, I ran premium and always hit empty, filled up and hit the RPMs while in 1st gear. No problems ...

 

did you scan the car, what codes are you getting? how often do you change the oil?

 

Haven't had the codes scanned yet - my Mini dealer is about 30 miles away and I haven't had the time to get there yet. I was hoping for a DIY fix that I haven't thought of yet. As for oil, I change it about every 7500 miles and almost always at the Mini dealer and if not, at the local independent BMW/Mini specialist.

 

7500 is too long even though that's what mini recommends. I would do it every 5k at most for full synthatic. Since we dont know what the codes are, it will be like a guessing game.

 

Walnut shell blast is the solution, carbon build up for sure

 

A slight update: Still haven't had the time to get my car to the shop but Sunday, after a 40 miles road trip, I decided to try the 'ol Italian tune-up. I took her out to a section of a local tollway with a speed limit of 80 mph and often very little traffic. As I entered the highway, I put it in sport mode and put the pedal to the floor! I figured I was either going to blow the engine or maybe it help blow out some of the carbon. Immediately upon the hard acceleration (revving up to ~5800 rpm) there was a thick plume of white(ish) smoke - reaching 90mph in very short order! I did that run for about 3 minutes and repeated the process twice more. The second run produced less smoke on acceleration and the third run produced none.

It's been 4 days since I did this and I haven't had a stutter or stumble on a cold start yet. I know it's probably a short-term "fix" but it has worked so far. The Countryman now starts like the day I bought it 5 years ago.

 

If you think you have carbon buildup, and are planning to do an oil change in the near future, I would highly recommend running a seafoam treatment in all 3 places and go from there. That stuff is pretty magical.

 

If the valves are carboned up the only way to remove the carbon is walnut shell blasting. The engine is direct injection, meaning the intake valves are not washed by the fuel mixture. The fuel is injected into the cylinders and does not go through the intake manifold. How old is your battery and how do the battery connectors look, any corrosion?

 

Intake valves don't need fuel hitting them for Seafoam to work. It is put in through vacuum, which allows it to wash over valves and piston domes. Way cheaper of a start than to media blast.

 

I'm sure I'll need the blast soon but after my Italian Tune-up last week, I haven't had a repeat of the problem. I realize it (apparently) is a short-term "fix." My battery is original but still fires up immediately. Connects, pasts and anchors look as good as new.