Hi

Usually if you have a injector or oxygen sensor fault or any engine running issue with components like the ones mentioned this would usually lead to poor emissions and this being a BMW this has very strict emission monitoring system.This system monitors all components relevant to engine running and cylinder balance if the eml light is not on the only other thing i would recommend is that the engine management system fault memory is read as this would give very use full information of any faults that me be listed.

As for the transmission the only thing you could try is to drive car in sport mode if the fault does not occurs at all the switch back to normal drive if the fault occurs this could be the lock up clutch engagement that you can feel because in sport mode top gear is suppressed.What you may be feeling is what we call torque convertor lock up of the final gear.if this is the case only in extreme case should you replace the torque convertor.

Hi

at this stage i would reccommend having the engine management and gearbox management fault codes read as this info would be very usefull because there are so many factors that could cause the fault you are experiencing and guessing on cars like this can be expensive. I would run this by your local BMW main agent because they will know these cars inside out