Hi, I own a 2009 mini cooper clubman S with 96'000 miles and the N14 engine.

Recently we have had the check engine light come on and off showing codes P0300, P0302 AND P0304.

Which is a misfire on these cylinders. We have our own diagnostics machine as well as a family member who is a mechanic and has his own professional diagnostics machine.

Firstly we changed the plugs and the ignition coils, and this certainly made a difference in how the car drives, more responsive etc.

However after a couple of days we get the codes again on cylinder 4, P0304 and P0300.

After a lot of research online, reading posts and forums, watching youtube videos it was apparent that my car could be suffering from carbon build up. So I got that sorted out.

However today when starting the car it immediately stalled. So I tried again and it started, however this time around there was no response from me putting my foot on the throttle pedal, no revs, just idling under 1000 rpm then it stalled. So I tried it another 3 times and the same thing before eventually pushing the pedal down got the engine to rev. Once I get to this stage it drives just fine and better since having all this other work done. But leave it a day and the same problems above and I noticed a bit of smoke and smell around the car, maybe too much fuel burning or something.

So I am at a bit of a loss as to what the issue could now be. Could it be the throttle body needs replacing, but I am not sure that would have anything to do with misfires on the cylinders. Could it be the fuel pump issue that bmw should cover up to 120k miles?

I am at a loss and wondered if anyone on here had any ideas?

Your help would be much appreciated.

Regards
Kevin

 

Any luck resolving this issue? I have an 2009 R56 with 91K miles, and just got the same three codes.
I'm contemplating ordering new coils based on the mileage.

 

timing chains are known issues for going bad and causing your issues. there could be fault codes indicating this or there may not be. get that timing checked and the timing chain assembly looked at.