Hey! I have an 07 MCS with 56k on it. I just got it back from the dealership last week for some recall repairs, but also for a power loss/hesitation issue that the dealership says was due to carbon build-up. So, it was walnut-blasted.

1 week later (today), acceleration is excellent - no more hesitation or sputtering when trying to accelerate. However, I have noticed that one issue still remains that is pretty frustrating.

The car stutters/hesitates at very low, steady speeds. Only happens between 20-35mph. Maybe RPM related? Best description? Think of when you're driving a manual and you're cruising at too low of an RPM and then your car starts to sputter - you hear it in the drivetrain and feel the car kind of jerk. That's what my automatic MCS is doing.

I feel like it may be RPM related .. except that it ONLY happens between 20-35mph. Never any other time. Any ideas what could be causing? Is it normal in the MINI's?

 

Wow, guess I stand alone ..

 

No, you don't! My 2011 CMS Auto does the same thing... Mine feels as if your pressing the accelerator and then letting it go in rapid succession (kinda like on/off/on/off). I Thought I was just being paranoid and I was feeling things that didn't exist. I have to take mine to the dealer for other issues (battery draining and very low mpg, cannot get more than 17-18mpg no matter what I do) I'll let the dealer know and see what they say.

 

Yes! Exactly what mine feels like.

I've literally spent the past 1.5 hours searching these forums for possible ideas. So far, the only one that seems to be similar is the high-pressure fuel pump. However, I don't know that it may apply to my case since the issue literally only happens during low RPM's, and I have no issues on start-up.

I tried to glance at my tach tonight on the way home from work whenever I felt it .. and it seems to be doing it most often between 1500-2000 RPM's. I was even able to duplicate the "hesitation" at about 40mph/1800rpm's. I'll be calling the dealership first thing in the morning.

 

+1. I have been to the dealer. Their response as expected "Can't be duplicated".

 

First of all, I am offended. I'll have you know that I am an awkward jerk at all speeds .

Seriously, though I have been experiencing something similar. I have a 2013 MCS Roadster with almost 20,000 miles. In the last few weeks I have started to notice the hesitation/jerk similar to what you are describing. It is not turbo lag because I know what that feels like. In every case it has been after driving only 4 - 5 miles so maybe the engine isn't completely warmed up especially now that the weather is starting to get colder. It has never done this before, though, whether the engine was cold or warm and not even last winter in sub freezing weather. It has happened with me when I was cruising along in sixth gear in the 2500 - 3000 rpm range and pressed the gas pedal to accelerate. I thought maybe it was a carbon build up issue starting even though I only have 20,000 miles on the N-18 engine which is supposed to have less of a problem with carbon than the N-14. I haven't taken it in to the dealer yet since it has only happened two or three times and I have had trouble trying to duplicate the symptoms.

 

At 56k miles, maybe your transmission fluid needs to be changed.

 

ahh, The infamous "can't be duplicated" response. I will give them a step-by-step on how to duplicate the issue.

bahahahaa, I needed that giggle. On to serious matters ..

Interesting in such a low mileage MCS. It is definitely not turbo lag, turbo lag doesn't give you the jerky feeling. It's like when you're driving a manual and you are at really low RPM's and the car starts to jerk, that's what it feels like to me. For my MCS, it's definitely NOT due to carbon build-up. I just had the intake valves blasted at the dealership 2 weeks ago. For you, I can't imagine at 20,000 miles you already have build-up issues. That'd be absolutely insane.

It only happens when I'm doing speeds between 30-40mph, and it's most prevalent when I am trying to maintain a steady speed. Acceleration is on point, no hesitation at all. Just this odd jerking when I'm maintaining a constant 40mph, for example. I've tried to duplicate the issue by maintaining a higher steady speed, but at the same RPM's as when I'm doing 30-40. No such luck. Only happens at those low speeds. I haven't had time to get it to the dealer, but hopefully I can do that next week.

Maybe but .. if that were true, wouldn't it present itself at all steady speeds, instead of just mildly low speeds?? It just seems odd.

 

Hey Guys,

I have a similar problem with my MCS 2007. I get jerks at low speeds like when I move from a traffic light or from a STOP sign I notice a sudden jerk and the RPM suddenly raised. The dealer said he has to replace the transmission costs $8K, which I don't want to. Has anyone fixed such issues.

 

hi guys
has anyone able to resolve this issue so far? or any suggestions to the cause?
i have a 2008 cooper r56 auto tran and 73k.km on clock, it behaves somewhat the same way as described in the thread
at low speeds/in traffic jam when you constantly working with throttle, car jerks/bucks/kicks back and forth(occurs 75% of the time, it feels like sitting in manual car with a very bad driver), sometimes throttle response is slow, like the tran is confused which gear to use next. very annoying indeed.
what i've done so far:
changed plugs
changed transmission oil
engine oil changed
air filters changed
performed carbon cleaning.
throttle intake cleaned
issue persists.
no errors or codes on diagnostics.

doesn't occur when launching off, has different effect when cruising at speeds above 60kph, when letting of throttle and then reapplying it there is a noticeable "gap" like on and off. but it doesn't bother that much.

 

I had a similar issue with an auto transmission on my 96 Ford Thunderbird. In my case it was one of the shift accumulators and a solenoid. I replaced the accumulators and a shift solenoid and it shifted like new. The jerking is it trying to change gears. Don't have an automatic MINI so I'm not sure what's involved. I can tell you when I tried to have a local garage do the work they said they wouldn't and that I ought to get a new transmission. Instead I ordered the parts and did it myself. That was probably seven years ago. She's still going strong with the same transmission at 21 years. The easy solution for any problem is replace to whole unit. It requires very little thinking.

 

Has anyone resolved this issue? My MCS has the same problem. During low speed, it will stutter or jerk. It can be really annoying. I remember when I first got the car, it wasn't like that until I did an engine oil change. Maybe it has too much carbon build up also.

I already changed the transmission fluid, spark plugs, k&n air filter, engine oil, alignment, tires, coolant, and the battery this year. My AC Compressor is giving out but thats another story.

I really think its either the carbon build up or fuel pump. The fuel pump makes a clicking and vacuum sound on the bottom rear and there is also a vacuum sound coming from the engine bay.

I will bring it to a shop to get it checked out this week but in the meantime, does anyone have an update or solution?

 

Did you get it fix?

 

Hi All

Good afternoon. Still no fixes after so long. Own 2010 MCS n having the same problem as well. Changed both HPFP and Fuel Pump, still having the same problem.