I have an '06 MCS that I picked up at the end of October new.

Today, I got in my car and started it up, no problem. Temp outside was about 40 degrees, sunny. Overnight it was pretty cold. I was in the driveway and about to leave but needed to go back in the house, so I turned the car around in the driveway so I could just drive out and not back out, then turned it off to go back inside to get a few things/lock up.

Came back out, started the car up (let it warm up a bit because even though the manual says not to let it warm up, my MA told me yesterday that for superchargers I should let it warm up ).

Anyway, as I'm sitting there, foot off the accelerator and car idling in neutral (and heat was on, but low), the engine sort of choked a bit. It was acting like it was about to die, almost as if it were running out of gas. I didn't touch the accelerator and it finally finished what it was doing and recovered to regular idle. After that, I was out motoring without any troubles.

Anyone know what this is? Is this the cold stumble even though it wasn't that cold out? The weird thing is I had had the car on just previously for about 2-3 minutes while I was moving it. Then turned it off, went in the house, and then back on again.

Is this something I need to have checked? Thanks for any help.

 

Sounds like the "cold start stumble"

Do a search and there is a huge thread on this problem.

Some attribute it to a change in gas (which seems insane) but its a well-know, real problem.

BTW, it has nothing to do with how cold it is outside but rather the engine being cold.

 

Also sometimes you'll have a little hesitation when pulling away with a cold engine. BTW, I almost never warm the car up - only if my DW is coming along for a ride. Warming up just wastes gas and you'll warm the car up faster with the engine at the higher revs. Pull away after 10 seconds or so and you should be golden.
I stayed at a Holiday Inn Express last night so I can say these things. j/k
:-)

 

It probably was

 

thanks chows... i thought the cold start stumble was mostly associated with the car moving. mine was stationary.

i'll search for the thread.

 

I thought the cold start stumble was on the initial start, not when already running.
My car does what mini_dreams is describing, if i'm in a drive-thru line or something, the car will be idling fine then all of a sudden start to idle real low and feel like it's going to die until I goose the gas pedal. I thought I read somewhere that it's the gas tank venting back into the system(?).

 

why aren't we supposed to warm up our cars?

 

Not sure about the reason, but if you consult your owner's manual, it states as follows:

Do not allow the engine to warm up with

 

yeah, what's weird, is that usually after I start my car, I sit for about 1 minute or 2 in the driveway, not so much to warm up but to put on seatbelt, plug in ipod and find some tunes. I read that too in the owner's manual.

to make things more confusing, and MA at my dealer said that you are supposed to let the superchargers warm up a bit. so i don't know whether to let it warm up or not.

another question - is it myth or not that you are supposed to wait until the light near the gas gauge changes from red to orange before starting the engine?

 

I have an '04 MCS with 18K on it and I have a similar problem.

I spoke to Mini about it and my service advisor said it was related to the brand of fuel I was using.

The issue: sometimes it goes into what I call "lope mode", like it's got a high lift cam or like a V8 running on 5 cylinders. It doesn't matter if it's hot or cold, but I did determine that it only does it when I run a certain brand of super unleaded. I switched brands and haven't had the problem since... but only time will tell.

Good luck.

 

I had the same problem, but I'm hoping it's just bad gas. My MINI's been running rough ever since my last fill up. I'm almost at half a tank, so I'll fill up again pretty soon...then I'll know for sure.

EDIT - double post - feel free to delete.

 

I had the same problem, but I think it's just bad gas. My MINI's been running pretty rough eversince my last fill up. I'm almost at half a tank, so I'll be filling up pretty soon. Then I'll know for sure.

https://www.northamericanmotoring.co...ad.php?t=92366

 

No. Cold start stumble is when turning on the engine cold, not while driving.

The OP started the car. Shut it off quicky (Not hot). Came back out and started and got stumble. That is stumble. Your case you drove and got stumble while hot in a line ... I dont think that is the same issue.

When I got cold start stumble, well my wife was driving the 04 weekdays and got fed up with the car. It just wouldn't keep running when cold until about the 2 or 3rd try. Turns out I had Switched gas to Shell and the car ran like crap. After getting through the tank and switched to Exxon, car ran fine again.

The fact that changing the brand of gas can have such a dramatic effect was a pain.

 

in terms of gas, i've been running the same gas from day 1. my road trips have been small, so i've always filled up when i get home at the same gas station. it's a no name station (not shell or exxon) connected to the grocery store I go to, because they discount the gas about 10 cents if you shop at the store frequently.

i'm running 93 octane, too.

i guess it's possible they got a bad batch of gas, but i was almost completely through this tank before the stumble.

strange. i haven't had it since... knock wood.

guess i'll experience filling up at different places when i motor out to Vegas. i just want to make sure there's nothing wrong before i drive 20+ hours west.

i'm at 2,500 miles now and will get my oil changed before I go to Vegas on the 19th

 

It could be just some "bad" gas ... whatever that means.

 

Aside from the obvious joke I could easily post in there....

What I understand bad gas to be in MINI terms is any gas that has ethanol. Ethanol is an additive that holds on to moisture. As the moisture in the atmosphere in and around the Storage tanks at the gas station increases the gas gets contaminated, and which gets into your gas tank and starts to corrode the seals on the pump in you tank. The ethanol additive bonds to water molecules.

This additive is added in at the gas station. Not by the carrier tanker.
Some states have it posted at the pump that they are using it in their gas, other states do not list it as it is a statewide law that they pass to use
what I like to "corn gas" exclusively.

If you think you are using a station's gas that has the additive, it is a good idea to add a can of dry gas occasionally, particularly if it is raining or very humid outside.

 

I've mostly filled up with Shell since new and I've always had the stumble. Lately I got the dealer reflash that is supposed to fix the stumble and it didn't help at all.
My brother found out that a friend of his with a Land Rover has similar issues and traced it to the brand of gas.

I was not convinced but decided to give it a try. I haven't had a stumble since changing brand of gas, now going on three weeks.

Seems "English" cars don't handle "English" brand fuel too well

 

While the above is true, "bad gas" can be from many things, wrong mix of additives not ethanol, water, dirt, etc. I am talking off the top of my head but "bad gas" and the troubles it causes has been around much longer than ethanol.

OR, is this "bad gas" a myth to be busted?

 

"bad gas" can also be gas pumped out of the bottom of the tanks that has absorbed water. I guess you dont want to fill-up just as the tanker truck pulls up