Last night as I was leaving work I had a check engine light come on (yellow). It was around 20 degrees with some snow and ice on the ground. I checked my oil and carefully drove it home. Today I took it to my mechanic and had him pull the engine code. He said the code was about the engine not getting up to operating temperature (or something along those lines). Is this a common code and is there anything I should do if it comes on again?

 

Haven't had this on my MINI yet but on other cars the P0128 (I believe, going from memory here) usually means a thermostat replacement. Thermostats sticking open = slow to get up to temp. The MINIs are a bit different though with their multi path DME controlled valves. Hopefully someone else chimes in, but I would plan on a thermostat housing (MINI is an integrated thermostat housing).

 

I've been losing coolant so maybe it is a thermostat housing problem.

 

Look and see if it is crusty. It is on the driver side, behind the vacuum pump, about the middle top/bottom wise. Look down from the top of the engine for all the coolant hoses.