Background:
My 2010 Mini Cooper S (with 130,000 miles on it) has had it's water pump replaced twice already. As well as the timing chain, fuel pump and misc. things.

Current Situation:
Driving to work and notice the heater was intermittently blowing hot and cold air. Weird, but okay. Later that day I had to drive an hour away to pick up my brothers girlfriend for her doctors appt. on the way home, it displays the yellow temp warning light. Shut it off, called my brother to bring me coolant. When he arrives, there is coolant coming from the front passenger side, somewhere. We top it off the coolant (it was obviously low), start the car and it boils over. Not good. I need to get it home. So, I put the cap back on and get it home without any issues. When I park it and turn it off, no coolant was leaking.

All this leads me to think it's the thermostat housing (which I have the skills to replace). The last two times I had to replace the water pump it just dumped coolant, never retained it. But I could be wrong. If it's the water pump, I'll need to bring it to a mechanic.

What do you think?

 

Did you ever get it fixed? What was it?
if not... the water pump is on the passenger side, the thermostat is on the drivers side. So my guess would be the water pump.
Mine just started doing the same thing, just a small, almost intermittent leak on the pass side. But I can see it coming from there. Is there any noise? I’ve noticed a sort of chatter (close but not quite the right way to describe it) since it started leaking.
At least compared to many other parts, a water pump is pretty inexpensive to buy.