I have an 09 factory JCW with about 6,500 miles and we are entering the beginning of the Texas summer. In the past two weeks the temperature has been anywhere from 75-95 degrees. During the last two weeks, on three different occasions my car experienced a loss of power when starting off in first gear. It's weird to explain, but when this has happened the engine did not sound like it was sputtering for air like a car would typically sound if someone stalled it going into first gear. Instead, the RPMs just dropped too 500 (or below) and seemed to stay there for a few seconds. All three times, I floored the accelerator assuming that maybe I wasn't giving it enough power, but when I floor it in these situations the car takes several seconds to respond at all.

The first time it occurred, I was turning left across oncoming traffic and I had to go up a small incline maybe 3' tall at a 45 degree angle. I accelerated normally as I have at that same intersection before, but the car did not respond at all and just barely crawled. I floored it, the RPMs popped up after 3-4 seconds and the car seemed fine again. The A/C was not turned on when this happened.

When it happened today, I was pulling out of my driveway, on an even pavement surface. I went to accelerate as I normally would and the RPMs just fell down regardless of the amount of gas I gave it. After flooring it for 3-4 seconds, the RPMs popped up again. The A/C was turned on when this happened and it was about 95 degrees out.

Since I picked up the car in the fall, I have never had to use the A/C before the last two weeks. I have noticed that it makes a very loud and noticeable sound when you turn the A/C on after you start the car. It sounds like it makes that little engine work as hard as it can, and I am somewhat curious if the amount of stress the A/C puts on the engine could partially contribute to this problem. Even though, the A/C was not turned on the first time I experienced this problem.

I can't stress enough that when this has happened, the engine sounds and acts differently than it does when an inexperienced driver stalls at launch. I have about a decade of experience driving a manual transmission, and have not had any stalling issues with my MINI since I picked it up in October 2008. I am curious if anyone else has ever experienced anything like this, particularly in warmer climates. Anyone else have a similar experience in their factory JCW?

 

I live in Houston, my JCW now has around 7500 miles, and I always leave the AC compressor on to dehumidify. Although not exactly what you're describing, I notice it's much harder to take off from a stop smoothly if I DON'T have the Sport button on. Without Sport, there seems to be a throttle lag on take off, pretty much unnoticeable once started. For that reason more than any other I always leave the Sport button on. If that's not it, sounds like you might ought to have the dealer check the ECU and make sure there's not glitches before it gets you into a dangerous situation.

 

Thanks for the reply. I haven't really messed with the sport button too much, but I will try it out.

 

If your close to the dealer or remotely close, I would take your 09 JCW in for a check.

Dropping rpm and lag is not normal. Sorry to say.

A number of folks with the manual find the MINI clutch interesting to modulate from low rpm, they use the sport button technique too. It appears to hold the rpm up a bit when in sport.

Have your dealer check it and make any changes necessary.

 

Yes, I will definitely take it into the dealer soon as well!