Update: Turns out, three of my coils went bad on the same day. I tested the fuel pump, checked the fuel filter, and everything checked out. I switched out the 3 ignition coils (1, 2, & 4) for my original Bosch coils (thankfully I had stashed them in my garage) and the car fired right up. The Duralast coils I put in last November have already been replaced twice (usually only one would go bad at a time). That being said, I wouldn't recommend Duralast coils to anyone in this forum. They seem to be poorly manufactured, as the OEM Bosch coils had never given me a problem in the 12 years I had them.
Additionally, I found that the thermostat issue was caused by the ECT sensor not being submerged, due to an air bubble. Poured a bit of water into the hole on the thermostat, and when I placed the ECT sensor back in, I immediately had heat and a proper temperature reading.
Everything runs perfectly now, and I am relieved that I didn't have to take a costly tow to the mechanic.

Hey folks--I am at a loss. So far I have been pretty good at diagnosing and fixing minor issues with my car (2010 Clubman, manual transmission, 138,000 miles) in the 13 years I've had it. I take the car in fairly regularly for a multi-point inspection at the independent Mini shop, but my nearest dealership and independent shop are both 2+ hours away, and I've never been able to trust any of my local shops to handle an oil change correctly, let alone a repair. A few days ago, temperatures started to drop down into the 20°F range for the first time this fall. I noticed that I wasn't getting much heat, so I assumed my thermostat was starting to go bad, and kept an eye on my engine temp to make sure it wasn't overheating (it wasn't). But yesterday, shortly after I started driving to work, the car developed a random misfire, and an extreme loss of power. I keep a code reader in the car with me, and these are the faults I had--

P0300 - Random Misfire
P0301 - Cylinder 1 Misfire
P0302 - Cylinder 2 Misfire
P0304 - Cylinder 4 Misfire
P112B - Coolant Temp too Low
P0137 - O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) <--- possibly a side effect of the incomplete combustion?

I left my car in the nearest public parking lot I could get to, and my husband picked me up to get my truck so I could drive to work. After a little bit of research I decided I would attempt to get the Mini home in the evening (about a 15 mile drive). It was a super rough start, and I made it about 1.5 miles down the road before it stalled on a blind hill (on a rural highway, well after dark). I couldn't keep the engine running long enough to put it back in gear, so I had to call a for a tow. I can still get it to turn over, but the car shakes violently and immediately stalls.
I wouldn't imagine this is all caused by the thermostat, unless it's just because the coolant is flowing into the cold engine? I replaced it ~70,000 miles ago, but the symptoms at that time were nowhere near this magnitude.

I either have to fix the problem myself or tow it the 2+ hours to my mechanic, because I currently can't even drive it. Has anyone else been through this before, and how did you fix it?

 

When was the last time plugs and coils were changed? If the thermostat was failed open, not sure I would expect the car to run rough like that, just throw a low temp code. Oxygen sensor 2 is the downstream sensor, which only monitors cat converter efficiency.

 

I should have mentioned, I changed my spark plugs, coils, and downstream O2 sensor about 10,000 miles ago!
I can't remember if I changed my temp sensor at the same time as the thermostat, since that was so long ago.

 

Hey Nik,
Looks like you were on to something! Somehow, three of my coils went bad on the same day. The Duralast coils I put in last November have already been replaced twice (under warranty), so I decided to cut my losses and bought new OEM Bosch coils. Lesson learned!
The temperature issues were due to air in the line, so I took care of that and we're back on the road!

 

Yep get bosch , Delphi, or the Bav Auto ones, I have the Bav Auto ones and going strong. The less known ones can take the heat cycles and fail more then the OEM ones. Most of the time its one coil, three means they have quality issues with that brand.

 

I went ahead and bought a set of Bosch coils! I told my dad what happened with the DuraLast coils and he said they should change their name to Doesn'tLast. For a grand total of 7 failed coils in a year, I'd say there's an engineer or quality manager somewhere who hasn't done their job!