Will try to pull it tomorrow. Raining right now.

 

For P2187 (272C):

 

Think this may be the issue...

 

Looks promising!

 

Fingers crossed. Going to try to patch it until I can order a replacement.
ECS has it for less than half what the local Mini dealer sells it for

 

What's the patch strategy?

 

Hondabond, for now. Should fill the crack & remain flexible, and it made for high heat application.
If that does it, I'll order a replacement from ECS.

 

Good luck.

 

Reinstalled this morning, idles great cold.
Will need to get out for a drive & see how it holds up

 

Awesome preliminary outcome.

 

Took a little 15 mile loop to get some gas. Mix of highway & stop/go.
Still a little stumble as it drips to idle, but idle is smooth after that.
Checked codes & still have a cyl 1 misfire, but no more MAF nor lean condition codes.

 

Post the cyl 1 misfire code.

As mentioned previously, you'll generally learn much more from the BMW fault codes. I have Car Scanner ELM OBD2 Pro on my iPhone. It cost $7 and pulls BMW fault codes as well as my Launch scan tool does.

 

P0301, 2783, 2773

 

Wondering if it may self tune part of it out, now that it's getting proper afr.
First few stops, it was a pretty rough idle that got progressively better.
Just the mild stumble right when it drops to idle now. No rough/stumble idle.

 

It may smooth out, but given the persistent cylinder 1 misfire, it probably won't.

 

If you think your spark plug and coil swapping tests strongly ruled them out, then you should check fuel injector 1. if it's fine, doing cylinder compression tests may be warranted.

 

I've still got some spares I can swap out to really try to rule out plug/coil. Could also swap coil/plug between 1 & 2 to see if it follows.

Pouring rain right now, so that's a no go at the moment.

 

I'm in Southwest Houston. Last year, we got almost no summer rain. This year, we are getting a good amount, and my wife is happy with her garden.

 

I'm between Spring & The Woodlands. We got a good pour this afternoon & are headed to the Astros game this afternoon. Hoping it dries out enough to have the top down

 

 

So far, so good.
Made the drive downtown for the Astros game, and home. A few idle stumbles while in traffic after the game.

Took my youngest kid to school this morning & idled my way through the dropoff line without incident.
A little stumble when I parked at the office, but it's significantly better than it was with the massive intake air leak

 

Cyl 1 misfire still present, now when it gets warmed up & only at idle.
If I slow to a stop gradually, it seems to be able to hold idle, a more rapid decel & it stumbles pretty badly.

Going to swap the plug/coil again & see if it has any effect.

 

If you have a little time swap one cylinder at a time and one of the two (coil or plug) at a time. Best way to identify faulty components.

 

Swapped cyl 1 coil & plug with a spare. No change
Thinking something else at fault. Some oil on the plugs so I'm guessing either vc gasket or piston rings getting oil in the comb chamber?

 

If your focus is the cyl 1 piston rings, then do wet versus dry compression tests comparing cyl 1 to the other cylinders.

I don't think a VC gasket issue would cause misfiring.