Hey, there.

2012 Mini Countryman S, 6-speed.

Wondering if anyone has a clue about what could be causing this. It only happens under full throttle/very near full throttle. It only happens between 3000 and 5000 RPMs. It feels like a miss in one of the cylinders. It happens 1 - 3 times very quickly in each gear, then stops (or I upshift). I get a pop and burble from the exhaust at the same time, similar to when I downshift. No smoke, no warning lights. Though I haven't yet hooked it up to a scanner to see if there are any codes that just weren't severe enough to trip a light.

Things off the top of my head I could see it being, no particular order:

1. Dirty fuel filter that chokes under high demand
2. Spark plug that is fouled and doesn't burn correctly under high load
3. Fuel injector started to get clogged that doesn't spray the full amount it should under high load.
4. Waste gate is activating early, and dumping boost.
5. Some issue with a cylinder, maybe compression or valve issue.

One guy I read about had a very similar scenario but on an '02 Cooper. Ended up a piston head had a chip or hole or something. Had to have all the piston heads replace, and the top end rebuilt.

 

Miles? Certainly look at the plugs and the OBD codes are all important. Several codes were present that only a true BMW/MINI level scan showed. My reader never saw them.

Mine did this randomly over a years time and eventually the HPFP code popped up and was replaced under warranty. Could be many things however.

 

Plugs and or Coils. My 2012 did the same it was plugs

 

how many miles? I will say forget the book on replacing plugs- I got my R60s with 45K miles on it, after driving it home from the sellers (500 miles away) I started noticing similar stuttering, lack of power stuff. changed the plugs- plugs I pulled out were rough looking. New plugs from ECS Tuning went in and there you go- feels like a fresh engine and has power back in all gears through all power bans- no stutter.

change your plugs

 

I had the same issue when the car was around 55k miles and I started with the least expensive to most. I cleaned map sensors first and that didn't fix it. 2nd replaced spark plugs and I can tell visibly they were bad. That didn't fix the problem. replaced all 4 coils and that fixed the problem.

So in conclusion my issue was the spark plugs and coils. 3 months later one of the new coils went bad so I put one of the old ones back and car is running great again. However now my clutch is slipping so theres that.

 

Leaving/using plugs for too long will ruin coils. As the gaps get bigger and tips corrode, it takes more amperage to create spark..this makes the coils and wires run a lot hotter and burn up over time. Also, make sure all your plugs are torqued still...they can loosen up and back out over time.

*less gap = less energy needed to make spark, more reliable under boost
*more gap = more energy required, may blow out under full boost, best for full fuel burn efficiency

**if you're using aftermarket coils you could run a larger gap and burn more of the fuel already being comsumed..but stock won't handle it.

 

I think you may be a bit confused on this matter:
the ECU doesnt "increase amperage" to suit the spark plug demand. It cant read data related to what the spark plug is doing when it fires. the amperage is going to be the same no matter what. the coil pack design can only do so much with that amperage- hence why the upgraded packs are more expensive, they condense and transfer the available energy in a more efficient manner than the oem. OEm is designed for "longevity" which the upgraded are designed for maximum engery useage/transfer.

the gap of the spark plug does not translate into the amount of energy "needed" to make it fire. it does translate into the temperature of which that spark creates it most efficient energy transfer and ability to ignite the mixture. some vehicles run an enormous gap because the volitility of the mix is demanding of that type of spark rating.

with regard to spark plugs as well- dont get confused of "heat/temperature" rating. thats not the "temperature" of the spark. thats the ability of the spark plug to transfer heat from the cylinder combustion, through the spark plug and into the surrounding metal. thus creating the ability for the spark plug to opperate at a specified temperature for the amount of heat it will creat by itself in its transfer of energy in creating a spark.

the only way to increase amperage in the ignition system is through condenser packs which harvest wasted energy, recycle it and add it to the next cycle of energy being sent through the wire system it is attached to. there is constant energy in the wires going to the coil packs, inside the coil pack is like a light switch flicking on and off. the amperage and energy going to or accesible to that pack stays the same though- its how that pack harvests and transfers that makes the difference.

running a larger gap with aftermarket coils will not "burn more fuel". it will create an inefficient burn cycle, and youll see a decrease in mpg due to the decrease in efficiency that the engine controls are seeing---- oxygen sensor detects fault burn cycle, which then asks the MAF what its doing, if the MAF says its doing fine, and the amperage going to the coils says its fine then the ECU assumes that there is an issue with the burn cycle and thus will dump fuel while adjusting timing ignition (when the coil pack actually transfers its harvested energy) in an attempt to save the cylinder or the entire engine. - does a similar thing when you knock- cylinder wall gets too hot due to lean air fuel and it will dump fuel to try to cool the wall down while retarding the ignition for a later spark. advancing the ignition cycle makes for a more "powerful" urn as the piston is still compressing the mixture as it is actually beginning the ignition cycle- creates an immense amount of stress on the crank, piston rod and pin- but makes for a hell of a combustion.

so- while it is not advisable to leave spark plugs which are bad in your vehicle- the bad plug wont "by itself" cause a failure of the coil. the coil however could cause a failure of the plug.

for best fuel consumption/power its best to allow the engineers to tell you where to set the plug gap based on calculations of fuel mix, combustion ratio, amperage rating for the vehicle system and a few other things which take too long to explain.

all good?

 

oh- and btw our vehciles dont have an accessible/servicable fuel filter. its in tank. and unless youve been putting stuff other than fuel in your tank- it should be good for a long long time.