WE have a 2014 Cayenne Diesel. We've been getting a coolant low warning. I have added distilled water to the system. I do not have any puddles & have not found any evidence of a leak. This has been about once a month for the last four months. I have not found any evidence of a head gasket failure either (white smoke when running)I'm wondering if anyone else has had this problem & what they found. I am not a fan of taking it to the dealer (nearest one is 2+ hours away) either. Since the diesel Cayenne is a bit rare, I thought I'd ask here if anyone has found coolant problems with the diesel.