Hello all!
First things first, thank you for taking time out to help meeee!
Sorry for the long paragraph ahead.

So this is my first mini.
To be exact its a 2011 Countryman S (R60).

My boyfriend was driving home from work and he randomly got a check engine light and the yellow engine light.
He was down the street from our house so he just drove it home and parked it.
When I got home, we did an OBD reading and got the codes, P0300, P0301, P0302, P0303 and P0304.
Misfire in every cylinder.

My first instinct was, spark plugs.
Bought the OEM grade (NGK Iridium) from O'reilly's and even made sure they were correctly gapped.
I torqued them to spec and everything.
Test drove the car, and the codes went away. The car ran great! Even better than before.

(Coils are still OEM spec to car. Did not replace them since they all are working.)

The next day my boyfriend took the car again to work since it was fine and then the exact same thing as mentioned happened again.
I took out each coil one by one and they were all working fine.

Same codes all over again.

Since the car needed the turbo to be replaced, I went ahead and assumed it had something to do with the turbo.
We towed the car to our friends dealership and he replaced the turbo for us.

The car still continued to misfire.
He is going to do a compression test to make sure each cylinder is performing as it should.

I read around a couple of forums that it can be the fact that I did not get true OEM from the actual mini stealership.
(Didn't know Mini's are THIS picky.)
I also read it could be the HPFP. (covered under warranty.)
I read worse case scenario is the pistons or the seals. (I don't believe this is it since the car is not smoking or showing symptoms.)

What else could it possibly be?

I am to the point where I am going to buy a whole new set of spark plugs but wanted to get more input before I take it to the stealership to run diagnostics.

 

How many km are on the car, and have you ever changed your timing chain?

The timing chain can stretch enough the Vanos cannot compensate and you get misfires, especially at higher rpms.

Related, have you ever heard excessive chatter from the passenger side of the engine when starting cold?

 

So I think in reading here that the coils were not replaced because they are tested as good. However, these things can be finicky and like most things on this mini that DRIVE ME NUTS can be INTERMITTENT.

The coils may get hot and break down and throw codes and then be OK. When I got some misfire codes a while back, I replaced all my coils as part of maintenance and have been good (did the plugs too).

Change your coils...

 

Is it possible that it’s bad fuel? Maybe only misfiring when water in the fuel is freezing?