I purchased my 6speed 2012 Mini Clubman S (n18) (82k miles) recently at auction. It's had intake valves cleaned or replaced at some point by a previous owner at the dealer 30k miles ago so I don't believe it's the issue.

To start, when I purchased the car it had been sitting for I believe 6 months on nearly an empty tank of gas. It fired right up, a little smoke from the tailpipe for a second or so, not really a problem.

I'm trying to fix this myself but I did have a shop check codes and all they could tell me was "misfire on all cylinders". They had a tech drive the car but could not reproduce The problem immediately as it is intermittent. I needed to use the car and could not leave it with them over the weekend so I took it home.

My symptoms: the car idles pretty well but it does wander very very slightly and you can feel very subtle vibrations. It shows absolutely 0 signs of misfiring while driving though until it jumps into limp mode at random. I turn it off and back on and all is well again. It happened a lot during the first few weeks of driving but it's much less common now. I can't help but notice it happens much more frequently when it's low on fuel.

My thinking is that it had some bad gas from those 6 months and now that it's had a few good thanks of fuel ran through it maybe it needs a new fuel filter to fix this.
The check engine light is intermittent but generally stays on most of the time. The car really does make great smooth power and drives nicely. 91 is what I run in it, the best I can get in my state.

I'll be checking codes again as well as the coils/spark plugs soon.

Hopefully this isn't a silly post but I hope you can understand the frustration. Just looking for some ideas or second opinions.



Edit: to add to all this, while driving it tonight on a full tank I remembered it also goes into limp mode when driving through a cooler spot of air. I drive with the windows down a lot and I can almost predict when it will happen when I notice the air temps change quickly. Usually at night. This part doesn't sound related to a possible fuel filter issue so I'm really not sure what I'm dealing with.

 

I would get as up to date on maintenance as possible. Change plugs and coils, and all engine fluids. If the codes are for multiple misfires, get the coils and plugs changed first.

 

I know it's a long shot but if you got this figured out, it'd be super helpful to know what you did to fix the occasional limp mode / misfires. My R57 has had very similar issues since I bought it - I recently made this post in the stock problems thread to get advice. Similar to you, my MINI had sat for a long time without being driven much so I suspect it has the same tank of gas for many months. I wonder if the issue might be in fuel delivery....will probably try changing the fuel filter as was suggested in my post.

 

Any updates on this? I am curious, like hokie_double_e, to know what is causing the limp mode.

While my MCS does not have any issues currently, I still am curious to know if the misfires cleared by the shop ever returned, or were those codes stored in the history and never cleared before you purchased your car? If the misfire codes returned, then yes, check coils and plugs. If you suspect a fuel delivery issue, then I think your intuitions are correct to (as a matter of course) replace the fuel filter. An NT510 Elite scanner ($190) will allow you to test and monitor (live data) the function of the fuel pump. I think live data on the scanner can also monitor the function of the high-pressure fuel pump and the Fuel Vapor Detection Pump -- the latter might coincide with fuel level and ambient temperature. However, your sense that the car does not seem to starve for fuel points me away from fuel delivery but more toward vapor management.

Be sure to look under the car and ensure that the downpipe catalytic converter and associated lambda sensors (O2) have not been modified.

Have you noticed that engaging a particular gear at a certain RPM causes the limp mode?

It would be nice to learn the verdict on this even if the source of the problem could not be found.

 

@keduMINI I'm not sure if we'll hear from OP since this thread was his only post and it's 2.5 years old. But as someone dealing with a similar issue I appreciate your advice. If it helps, I can answer your questions about my MCS since I seem to have the same issue.

For me, the misfire codes return whenever the issue happens. I usually don't clear them, but regardless they show back up when it goes into limp mode.

The downstream O2 sensor was replaced by a shop shortly before I bought my MCS, and it underwent a smog check after I got it so this stuff should be working alright on mine.

Recently I discovered that I could trigger limp mode by revving to near redline - this was usually in lower gears but I didn't test it enough to get a clear sense of pattern beyond that.

I don't drive the car very often and its runs fine aside from the occasional limp mode so I'm not in a hurry to get it fixed. My current plans are to change the fuel filter, then do a full carbon cleaning and go from there.

 

I'm following up on my previous posts in this thread in case it's helpful for anyone else who runs into this issue. My problem ended up being a crack in the air mass meter boot (air duct going to the turbo). It took a while to find since it was on the underside but once that was replaced and the turbo was getting the right amount of air, the misfires went away and haven't come back.

 

Thank you!-- this closeout courtesy is what gives online forums their strength, even if the reply simply states that "no solution was found (yet)" or "the vehicle was sold without a fix."

 

Sorry for the late response, I ran with this issue for a long time and forgot to update.

I really chased my tail on this one for a long time, it was not fuel related at all and it was completely random. The misfires were just codes, not actual misfires.

The misfire codes and limp mode were related to my dual mass flywheel being damaged and vibrating. I only got rid of all these symptoms after I did a flywheel and clutch job. I've never seen a limp mode since and I only get misfire codes when my car is actually misfiring.

I am dealing with new issues now, subtle boost variation and lag, power fluctuation day to.