I've had my 335i for a year and I have been dealing with problem for 8 months, recently it's gotten worse. I have to go out and buy a gallon of distilled water and Pentefrost NF every 2 days because it leaking will not cease.
There's also a bubbling/boiling sound coming from there that's making me kinda uneasy...
It started little by little, once a month I needed to add coolant. That turned in to once a week, and eventually
every other DAY. Dinan told me it was a leak by the rear turbo, Alekshop in Fremont told me it might be that, but the subframe needed to be dropped to look and be sure. I was hoping to go to another shop to get a 3rd opinion, but I don't know of many in the area besides the two.
If this has ever happened to anyone, I would appreciate any advice on the subject. I look forward to your replies.
Thanks