I have a 2012 MINI Countryman All4 S with about 65,000 miles on it and in July of this year it started stuttering while accelerating. When I step on the gas to speed up, usually around 2500 RPM, it'll start cutting out, almost like it wants to stall. It'll stutter repeatedly, and if I let the gas it'll stop. If I accelerate very slowly/gently, it seems to be okay.

Spark plugs were replaced, no change. We've done a couple bottles of Seafoam over the past 2 months, no change. Replaced thermostat & assembly because of a leak, but still no change.

Has anyone else run into this kind of issue? Had success fixing it? Is there any hope?

I'd really like to avoid having to take it into a MINI dealer, as I'm in Montana and the closest dealer is hours of stuttering away.

Thanks

 

only thing i can think of is fuel cut- like your not getting full fuel pressure.

have you cleaned your MAF?
removed the boost pipes and ensured those are all clear?
remove the intake ipe from the turbo and spin the compressor wheel- ensure it spins freely

 

You really need to have the codes read if you don't own an OBD reader. You can get an adapter for $10-$20 and apps that are either free or better ones for a few $$$.

Could be things from post#2, or High Pressure Fuel Pump, coils, etc. The codes will usually help nail it down.

 

Coil's - under $30 a piece 10 minute install.

 

Is there a check engine light?

I agree with the coils... it sounds like of them is bad. The N18 is known for eating coil packs, unfortunately. However, I would start with reading engine codes.

 

ke3ee just informed me regarding the coils premature failing- I would agree with them regarding these- If they are inexpensive then do that. I think either ecstuning or minimania has an ignition kit available for a relatively good price- like $150 for plugs and coils i think- seems pretty reasonable.

 

remember to put a quality non-petroleum based "lubricant" on the rubber areas before installing- on all my other vehicles i typically used Battle Born gun grease- non-oil based, resistant to high temps, protects against rust and wont deteriorate plastics or rubbers. is dialectic too

 

When this has happened to me, it precedes a coil fail. When that happens, you're not going to get more than 30-35 mph out of her, so I hope youre not far from home.

Anyone know the right coils to get- I have an all4 s, and the last coils I put in... I don't know- don't seem to give me the umph she used to have before. I also saw there were some coils that were specific to Turbo, after the fact.

 

They are made by Delphi. Same part # as most BMW 3 series. I get them from FCP. Cost approx. $25 each plus a bit of shipping/

 

I have a 2016 with 20k and Ive had the same issue on and off for the last 5k. Dealer replaced plugs once. No change, still studdered. Then the plugs and coil and so far that seems to have helped some. Plus make sure you are using 91 octane fuel from a good supplier. I prefer Shell.

 

Having this problem with my 2012 All4 S, 73K miles. I have replaced the plugs with no change. If I keep my foot on the throttle when it stutters I get a misfire code on cylinder 2 and it goes into limp mode. I can pull over and restart to restore full power. I have swapped the plugs between cylinders 1 and 2 with no change. I have swapped the coils between cylinders 1 and 2 with no change. I always use Shell 93 octane so it should't be fuel related, but possibly fuel delivery related? It almost acts like a plugged fuel filter but if I nurse it above about 4K RPM it will then run strong. A plugged filter shouldn't let that happen.

Please, anyone with experience resolving such an issue share your experience.

 

Replacing the coils resolved my issues. This German engineering is driving me crazy. The misfire condition or stuttering was only occurring at lower RPMs under high boost conditions. The ECM would disable the cylinder! I understand trying to protect the engine but by cementing the condition while driving creates a greater possibility of damage. I don't like that.

Anyway, doing more diagnostics I moved the coil from cylinder 2 to cylinder 4 and the misfire followed the coil this time. The plugs are new so I was confident that they were not the problem. I ordered a new set of coils (ULTRA-POWER 5C1749 S; S ALL4) from RockAuto for $17.28 ea. and they are exact copies of the originals. Took less than 5 minutes to replace and the misfire problem is gone.

 

For plugs make sure you are using OEM, anything you get at the parts store will still stutter, even when brand new....speaking from experience

 

Something I noticed when I tried changing the spark plugs the first time is that some so-called replacement plugs have a narrower insulator than the factory ones. This allows an air gap between the insulator and the rubber boot of the coil and the spark can then jump to ground. This is probably what causes the stuttering or misfiring. Some of the more performance oriented drivers use plugs with a copper electrode which are not factory. They will give slightly better performance but don't last as long as the factory ones.

 

IF youll do a search on the forum about plugs you will see that besides the factory Beru's which are now owned by Champion but a different line, NGK 1422's are the #1 recommendation. I have them in both of my CM's and have had no issues. #1 CM is at 75k and #2 is at 20k. both with Manic tunes. Some have used Brisk brand plugs with good success but most use the NGK's.

 

Could be one of the fuel pumps and it could be under their extended warranty.

 

Whoa there big fella. That HPFP is over a grand at the dealer and reading this forum has shown that it often does not repair the stuttering problem. Coils and plugs can be done in the garage for less than $125. It is a lot easier to try that than the fuel pumps. If you can get the engine up to higher RPMs the problem is likely not fuel starvation. Ya gotta use a little logic in the diagnostics so maybe you can save a few bucks. I know there is a definite problem with some of the HPFPs but make sure the problem is not somewhere else before throwing the big money at it. The Extended warranty for the HPFP does not cover the 2012 Countryman All4 BTW, only up to 50K miles. The dealership quoted me $2k for the job. Do all your homework when diagnosing your problems!

 

2016 CMS ALL4. 20,750 miles. I have had my plugs replaced twice, and my coils replaced with my plugs most recently. I thought that was the answer. Was better for awhile but now again randomly under fairly heavy acceleration load there is still a nasty studder/shutter. Startles me. Im wondering if its the JB+ I have installed perhaps? I know there is adjustment setting inside the JB+. I had my JB+ installed by the dealership and I've never touched it. Run shell 91 only. Back to the dealership for round 3 of this saga tomorrow. I'll update this group.

 

I was going off of my 08 MCS and the letter from BMW/Mini that extended the warranty to 10 years and 120,000 miles, figured it applied to the CM too. Just a thought just in case it was covered under warranty...

 

I just recently did some personal testing with my families Mini's and was able to repeat this issue on 3 different model Mini S models with 16K , 45K and 72K all with N18's on the same road and all had automatics.

Lets see if I can explain. My city is Hilly not flat at all... if we drove our cars on a flat part of the road at 40-50mph( sport mode didn't matter, JB+ didn't matter) and road started to have an upgrade or slight hill. Not enough for the car to downshift but enough to keep your speed the engine needs more fuel. The turbo has been spooling at low revs and as soon as you just put a bit more foot on the pedal the boost jumps from 1-3 PSI to 10 PSI.. It can build Revs or supply enough fuel to compensate fast enough so the ECU retards spark which causes the stuttering. We were all able to make our cars repeat this on the same part of road.


Make any sense?

 

That's what my 08 MCS would do under the same circumstances. I would also see a puff of smoke out the rear and then everything would return to normal. I've heard it called a super knock and it would never throw a code...

 

I only use 93 octane and in my 2012 R60 I have 100 Octane and it still can display the issue so if it is a " super knock" I don't know how to solve it.

 

In my case it was never solved because it wouldn't throw a fault. I also used the best gas available but I think it was more related to something not adjusting the timing during that particular situation. I ended up selling the car later on but not because of that, it would only happen when things were set up precisely as you described it so I knew not to accelerate at that particular moment. Do you also see a puff a smoke?

 

So I've been dormant lately (got a travel job so I rarely drive the mini) but as I started to get it in winter condition for the hills I hit the almost exact same issue. I'm wondering if the ground issue is what I'm getting as well? I have champion plugs in and delphi coils, all less than 500 miles on them in the last 3 weeks. Still no change. Also had the HPFP replaced (which BTW IS UNDER EXTENDED WARRANTY - did at Mini here in S. Denver) so it's not that. I'm perplexed at what to do. It's not chucking any codes. Just freaks out if I'm pushing hard at around 2-3.3ish k RPM's. Also seems more apparent in gears 4-6 than 1-3. Could I need to add some conductive gel or something to the coils??

2012 CM S-All4 70k

 

Is there a solution to this other than swap plugs? I put in champions and I'm having the same issue WITH new plugs. Maybe some type of spark plug grease or something?? Would you put something dialectric on it as @minimontes said or should I get some of the oldschool 12 sided plugs?