If I have this in the wrong forum, I appologise; the question comes from the problem, and is at the bottom of the post; the text that follows is for background...

2012 MCS with 10,000KM and have had 1 fail to start and many stumble events after start. MINI had the car for 3 days of 'perfect' weather to recreate the fault, and reported "No Fault Found!"

It failed to start on me only one morning - 4 start attempts where it would catch then die. +5C and damp/foggy after an overnight in the driveway. On the 3rd and 4th attempt, I had my foot on the gas, and was asking for a slightly open throttle, and when it caught on the 4th attempt, I nursed the RPM up to 1600RPM with the throttle. When it cleared its throat, it was fine, and the drive to work was uneventful...
The stumbles happen after a cold soak too, on cold damp days - +5C to -1C or so. I get a normal start, then as I am driving away gently, it stumbles and recovers. When I leave home, I drive down a slow hill, so low throttle, and slow speed. Once it has seemingly cleared its throat, the fault goes away, and does not repeat until cold soaked again. I think I may have noted it at idle as well - the rpm dips slightly, I get a pop from the exhaust (similar to a Sport mode "burble and pop"), and it recovers...
In most cases, a small 'goose' of the throttle seems to clear the problem, which brings me to my question:

Does anyone know the function logic surrounding the throttle plate during/after start? I understand it is closed or following pedal position command during start, then opens after some conditions are met, allowing the valve train to take over throttle function. I would like to know the actual logic/function and conditions, as I am beginning to suspect it may be a part or the culprit in my starting/stumbling issue...

Any help would be appreciated, as this is an intermittent problem, and I suspect it will be very hard to get the car, weather and BMW to cooperate at the same time!

Cheers,
E

 

Sounds like what mine has been doing and waiting to get it back from the dealer. I would check the thermostat, seems to be a lot of issues with them as of late

 

Had the same issue at 50K miles. The Dealer replaced the thermostat and now she's running like a champ!

 

Thank you both for the reply...

Sadly I did ask the dealership to take a look at the temp sensor, but they insisted there were no faults there or anywhere else. I know they could be wrong () but I have little recourse except to find other suspect parts and see if the symptoms fit... ...until the car breaks again. It does do the stumble once every 2nd start or so in damp weather (after it's had a chance to fully cool to ambient), but the symptoms DO seem reduced since I got the car back from MINI. I'm starting to wonder if it's as dumb as a bad connector somewhere; they played with it at the shop, all was good for a few days, and now the fault is back - and now, good luck finding the right connector!

Sigh... Thanks' again!
E

 

im on my second temp sensor, 15k miles...same symptoms as op, 2011mcs.

 

It sounds like the temp sensor. I JUST had mine replaced last week at 6k miles on a 2012 MCS.

 

I have had similar experience, though not so severe as Summons'.

My dealer had my car for two weeks. They left it outside, and did cold starts every day, but they were unable to reproduce the problem. Back at home, the problem occurred the very next morning and almost every day since.

The only difference I can discern is that I park my car in an unheated garage, which means a different kind of cool-down and startup ambience, without wind circulating under and through the engine compartment. Maybe this equates to higher humidity during cool-down.

I offered to buy a scan tool and submit startup data, but MINI was not receptive to this idea. I don't see how else this can get resolved.

 

video tape your start issues.

 

I have been doing that, but it serves no purpose if the engineers and/or district reps won't look and listen.

 

hey bud..

Just wanted say You are not alone with this problem.. I posted about it LOOONG time ago:

https://www.northamericanmotoring.co...nce-again.html

and got bashed that this is not a problem at all.. whatever.

so here is link above, You can see some videos I took.. Similar situation to Yours.. happened usually on very HUMID days.. and during rain or foggy weather.. when I took my car to Mini of Grand Rapids ... of course they could not reproduce the problem... sigh.

Showed them videos too, but it didnt matter.

This happens now and then and I dont really care anymore.. I am thinking of selling this car anyway.. to many quirks for a brand new car. Right now have 12K miles on it.

 

Molly2 is perfect in every other respect. So I'm not about to kick her out of the house for having a cold

 

Take the car ot them on a Saturday and leave it for them to look at on Monday. That is what I did and they did end up replacing the thermostat but also had to reprogram my computer due to a rough idle that they could not track down.

 

I had the same issue. First time around they replaced my MAP Thermostat sensor, then it did it again the following morning, so I re-scheduled and they took Becca in again and I showed the MA my vids and he agreed to hold it longer. Ended up opening a PUMA case (IDK) and found out it was defective intake and exhaust VANOS solenoids ( part # 11-36-7-604-292) and air duct ( part # 13-71-7-627-501). If they just keep throwing thermostats at it and it is still happening, ask them to look up the PUMA case on my car- 50378387 and that should help ya out!

~Clinton

 

Thanks, Clinton. I will send the information along to my SA

 

Bump for any other R56 LCIs with the same issue

 

My SA says they cannot look-up other dealers' PUMA cases. What kind of sense does that make, as a company policy?