I might add up to a couple of pint or so of distilled water.. anymore and I might pick up some coolant To combine. if it goes off again, bring it to your supplier. its most likely just evap lack of the drinking water part of the coolant mix. glycol https://buy-spoiler-for-car04948.activablog.com/26988042/details-fiction-and-types-of-coolant-for-bmw-335i