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https://www.northamericanmotoring.co...869#post404869

So yesterday I pulled up to a stoplight and when the revs got down to idle the car seemed like it was going to stall, but then recovered. It cycled through that behavior (stall/recover, stall/recover, etc) as long as I let it try and idle. It was cycleing like that about twice per second, the tach needle jumping up and down the whole time.

The car drove off smoothly from the light, and hasn't had the problem since. Is this a sign of some part failing?

If it helps, I'm running v.38, it was about 80 degrees out, and I had been driving normally for about 10 minutes when it happened. I've got an 04 MCS.

 

The same thing has happened to my May 04 MCS periodically. On average about every 200 miles or so. A little tap of the gas pedal usually sets it straight. I have read of only a few cases where it has become more of a regular problem. I had v38.1 flashed on the car about 300 miles ago and have not had the rough idle since. I also feel like it is a lot easier to start without a stumble when the air is on. The service dept. said that MINI is working on a fix for this problem (we'll wait and see before making any judgements about the fix). It does not appear to be a sign of greater problems to come. If it does become a regular it may the the spark plug wires or a couple of other issues, but as long as it is intermittent, it is probably an electronic control problem. I started a thread on this same topic on Under the Bonnet on this site and on MINI 2. V38 is not intended to fix this bug but I like the effect it has had on my MINI. The idle is more of a minor annoyance to me than a major problem, but if they do come up with a solution I will get it fixed.

Cheers,

 

It would be really unfortunate if this becomes an ongoing Mini problem. 80's BMWs were notorious for having crappy idles, and I can tell you from experience that it is incredibly annoying.

 

My 04 S does this once in a while too. A tap on the gas resets it. It's a little weird, but it doesn't seem to be much of a problem. The car runs perfectly otherwise.

 

My car actualy got worse when v38 was loaded. There was a rumor a few months ago that MINI was working on this, let's hope so.

 

My car was doing it once a week...and now its almost everyday. Its more embarassing than anything. Lauderdale MINI said it was a computer problem...

 

Our new car has this problem. Late model 2004 production S. -Pete, Stratmosphere

 

Same here on my '03 S.
Quite frequent for about the past 6-8 months. I'd say on average once per day on my daily commute to/from Boston. I believe I'm still runnin V.36.

I'd be interested to know if anyone that has replaced their coil and/or wires still experience these disruptions.

 

Same here in my 03 MCS. Does it most of the time at the same stop light on my way to work. Of course I do not always have to stop... I believe V.35 was in my car when I got it, and have not put in 10K to go to the dealer yet for v.38.

This is starting to have the beginnings of the Yo-Yo chronicles...

 

MIne has done this since new. (03mcs) The dealer cannot find anything wrong with it, though many cars have the problem. It has begun to happen at nearly every stop/idle now. It is a real pain in the a@@! I replaced the wires...nothing.

 

With the BMWs I've had the culprits have been vacuum leaks along the intake, faulty air flow meters, and faulty idle control valves. I have no idea if the Mini has an ICV, but as anyone checked this stuff?

 

This happens to me on occasion also... may '04 build. Like mentioned before, a quick tap on the gas and its gone.... tends to only happen when the motor isnt all the way heated up yet.

 

Ok, my wife today confirmed this has happened more than a couple times, all since the software upgrade. It sounds like multiple different software revs are having the problem, so I find it odd that it just started popping up. We had some other work done at the same time, but nothing that I can think of that would have affected driveability.

 

Mine's a pre-v36 and it idles fine after its warmed up, but it seems
very sensitive to humidity during cold starts.

For instance, if I start the car in 80%RH weather, the car will
idle roughly and unless I give it gas to back out of the garage
the car will usually sputter and worst case stall... very
embarrassing...

I have a thermometer in my garage that also measures humidity. I look
at the humidity before starting the car. It looks like 65%RH is the break
point. I put a big dot next to that number. If the humidity is higher
than 65%RH, I give it gas before backing out of the garage. If lower than
65%RH, then I just engage the clutch without any throttle and back
out without any idle roughness.

Some lacking ECU related programming on MINI's part....but too lazy
to get it reflashed since other then that, the car runs pretty well.

 

Relative Humidity might not be the answer. My 10/03 build MC does it about once a week, in Phoenix with 6% RH. Hmmmm.

 

uh oh...

 

I've experienced the rough idle problem several times now. It happens out of the blue when the engine has reached normal operating temp (04 MCS). The S/W was recently "upgraded" to V38 trying to resolve other problems.

Never had a rough idle prior to V38.

I think the ECU software has crossed over into the "too buggy to fix" category...

 

I'm in Phoenix too, and I have the problem as well.

I noticed it happens most when it is really hot, and I might be sitting in a
drive-thru or something. I thought it might have been some bad gas cloging up the fuel filter or possibly the injectors.
A while back, Phoenix had a rash of bad gas and so many cars had clogged fuel filters (as my Tahoe did) due to coal bed filters not being replace by gas compaines. That was my thought.
I am taking th car in on Monday for a wabble on hightway speeds and I am going to have them check it out then.

 

Since I have v38.1 installed, the idle problem happened twice within two days of leaving the dealer. However, I tried the unplug the battery for a half hour to reset everything trick and haven't had the rough idle for about 600 miles since. I know this probably means that it will happen again when I leave work today but so far, for me, 38.1 is a fix. It makes no real sense since others only have the problem after installing v38.1. I agree it's more embarrasing than anything else as long as it doesn't become a regular thing. When it was happening, it did happen most ofter right after the car had warmed up.

Cheers,

 

i have 04MCS and I have experienced this problem once, only once. happened 2 weeks ago as i drove into my garage and parked it. it was weird coz the revs were going up and down and my foot wasnt even near the peddle. i guess they becoming more and more like the old minis and getting a life of their own.

also, i do have a strange problem when i redline off of traffic lights..... my cellphone and coins always fly out of my pockets. any clues whats wrong?

 

There is no CD38.1 - only CD38. BMW doesn't do 'points' on their GT1 CD's, only whole number revisions.

That said, the idle problem isn't new. I've seen MINI's do it that have every software version to date.

 

Any idea if it tends to get worse or better?

 

No, it just happens on occasion, just as everyone has noted. My guess is the ECU is "coughing". No codes are created during the coughing process - and I have yet to capture the nature of the a/f and throttle angle during a cough.

It could be related to the cold-start problem, but I think that's just poor wall-wetting routines during startup. However, it could be just straight up crappy injector mapping. Why the choppy idle is only on rare occasion is still strange indeed. It seems to be only after the car has been idling for a bit, though it doesn't seem to be repeatable at all.

The mystery continues - what do you guys think?

 

actually for me it's quite repeatable. almost every time i get off the highway and come to a stop. within 10 seconds it starts. i get it at least once every other day. i think it's a fuel problem. i have a PDA dyno and was monitoring the throttle angle and ignition mapping. when it started stumbling the throttle angle increased and the ignition advance started moving around. it seemed like the ECU was trying to compensate for the stumble, not cause it. my theory was the EVAP system purging fuel vapors into the intake and throwing the mixture off. a simple test setup would be to splice a test light into the signal wire of the purge valve and seeing if the duty cycle increases when it stumbles.

 

It's happened to me after sitting through a drive through (idling for a few minutes) and approaching a stoplight (idling for a few seconds).

This had never happened to our car before having v38 installed and the 10k service performed. Is there something that they might have touched during the first service that could be causing this? A part not reinstalled correctly, or something that was bumped?

Another possibility - I drove the crap out of the car after the service to encourage the ECU to learn a more aggresive driving style. Normally my wife an I split time with the car, and it gets a wide range of driving. Could that have something to do with it?

edit: changed "first service" to "10k service"