Slow coolant loss f25 x3

[FaithfulBMW]

Hi guys,

I am having some slow coolant loss that doesn't really easily manifest other than a light on the dash every 11 months or so, its hard to tell where its coming from. Do these cars have a common coolant system leak spot? Other cars have a weep hole, but I dont think the electric fuel pumps or thermostat have weep holes, so where else could the leaks be coming from? Could my coolant tank cap be bad and not holding as much pressure as proper?? thanks

[JasonShell]

Slow loss all the time too here. Every time I open the coolant cap to check the level, I hear gas escaping pssssst noise, I guess coolant evaporates overtime, just a thought.

[FaithfulBMW]

Slow loss all the time too here. Every time I open the coolant cap to check the level, I hear gas escaping pssssst noise, I guess coolant evaporates overtime, just a thought.

Thanks for the reply. I guess that makes two of us. I was kind of wondering what the heck is going on because the cap coming off hisses showing it holds pressure!

[FaithfulBMW]

So just an update for anyone out there. There is a small coolant return hose from top of radiator junction near fron drivers side that returns to the coolant reservoir. Its called a coolant overflow hose. Bmw part #17128651298. This little plastic basturd was sitting on a wrapped wire harness and from the vibration it wore a tiny little crack in the hose and leaked coolant gradually. Will replace and protect with vulcanized silicone tape. So yeah possible cause for coolant consumption. To be determined. Thanks