overheating

So I've had my 2009 jcw for a little over a year and have fixed all the common issues, but just recently it has started overheating, causing it to steam and spray all the coolant out of the reservoir cap. It blew white smoke out of the exhaust before I realized it, but its only after it started...

Hi guys from the UK. I have a mini cooper R56 N12, 2008, 53k miles. So lets start: I went to the mechanic with an issue that the fan kicks in normally at around 108C but the problem was it doesnt turn off. The mechanic touched both of the hoses coming from the thermostat and the lower radiator...