I've had my mini a a fair while now but in the past few months it has been acting very odd and losing all the coolant from the reservoir and overheating.
First time it happend I was in standing traffic and heard a wooshing and gurgling noise inside the car. A minute later and the fan is coming on and the temp gauge has gone up to max. I drove another 5 minutes to home and waited for the car to cool a bit, checked under the bonnet to find the reservoir empty and floating just by the neck. Seeing as I'd checked everything the month before I.e the oil and coolant I found it a bit odd since they where all spot on and have not needed any topping up since I bought the car a year ago.
I got an engineer from bmw to come out and have a gander and he reckons it must have formed an airlock in it by filling up the reservoir and not opening up the bleed valve. I told him I havn't ever filled it up and it was full just a month ago. He told me to keep my eye on it in future, it's not a closed cooling system and sometimes leakages can happen through the pipe clips.
Roll on to Friday afternoon, Same thing again 5 mins from home and toodling along and the gurgling noise then a swoosh and overheating again. Arrive home and it's empty.
Now it's not empting slowly its doing it all at once I've been checking every 2 weeks. I'm taking it to the garage monday as asked by mini services. But the question is what can cause this? Any ideas is it common for mini's? I've already double checked the type of reservoir and its the newer type as I heard older versions used to leak!
Any help appreciated. Just don't want any head warpage