[rickyjones1209]

I had this warning come on about 2 months ago so I filled the res up to max with bottled water (didn't have time to get BMW coolant). Anyway I'd planned to get coolant sorted in future but the warning light has come on again today. Surely I can't have gone through all the water in the engine so soon? Is it leaking from somewhere or is it coz I didn't use proper coolant?

The engine hasn't ever been any hotter than usual.