Noticed coolant was low, but had just had it fully flushed and changed after thermostat housing replaced due to leak. Car became hard to start, found the plugs were fouled, checked oil and found streaks of milky substance. I had been running my car with OBDII sensor running on my phone to keep track of coolant and oil temps since there are no gauges in a Mini to tell you what is going on in your engine. There was no overheating, no low oil pressure, just a misfire at cold start.

Once we saw the milky streak in oil, we opened up the valve cover to find a coolant/oil goop all over the engine, down in the throttle, and in the intake manifold. This car should not have been running with the level of goop in the engine. We now have to pull the head, clean entire engine, replace oil pump, and possibly replace the head and who knows what else. Were I to take this to a Mini specialist (because you need specific tools to do this job) it would cost me over $3000 before they even determine where the coolant leak actually is.

I have three other cars all with over 140K miles on them (Volvo with 250K, and 1990 BMW) and have never had to do major engine work as long as regular maintenance was done. Mini has insufficient gauges and generic OBD codes so you are just guessing at what is really wrong with your car.