Okay just ran an experiment. Disconnected nozzles 1 at a time and blew/sucked through flex straw held at attachment point (very scientific). Passenger side the air moved pretty freely but driver side did not. Must mean check valve is inside of nozzle assembly and passenger side has failed. Makes sense as that was the more noticeable leak but it's also upstream of the other one. I will replace nozzle (and 2 clips I snapped in the process) and update.

Ended up replacing both nozzles. Works like a charm. Nice not having a message on the instrument panel.

Thanks for the follow-up! Good timing too as mine has been fine up until this past week when the fluid pulled a disappearing act again.

I checked the tank after driving home from work one night and the tank was under pressure (the cap "popped" when I took it off). This proved my theory that heat from the engine is pressurizing the tank. If the check valves go bad, this would explain why fluid would leak out of the jets when the engine is hot. I have also determined that the reason why the problem is somewhat random (and why the dealer couldn't replicate the problem after filling the tank up and "watching" it while it was in the shop) is because when the tank is full, there isn't much air to heat and therefore expand and push the fluid out. As the washers are used and the tank empties, more air is in the tank, expands when heated, and reaches a point where it can start pushing fluid out of the nozzles. I've also been wondering if a small (1/16") hole drilled in the cap would release the pressure and help the situation. Of course, I'm sure BMW engineers would have added that to the design if it were necessary :rolleyes:.

My cap DOES have a small pressure relief hole in the centre - I thought they all did.

There's evidence of fluid being forced from this vent (dry detergent) but I've never seen it actually wet. And I do get the occasional few spots of fluid on the bumper, under the splitter in the bumper. Not always and only a small amount.... A job on the list. ;)

Well, I drilled a 5/64" hole in the center of my tank cap and filled the tank. Let's see if the fluid pulls another disappearing act now...

If you washer tank is building up pressure you are missing this screen.

Yep - it's missing in mine.

The screen holds up the cap, breaks the seal, and allows air in/out. I think every dealer tech popped open the cap to refill the reservoir and out and down to the skid plate went the screen. Nobody is hunting down that one. :dunno:

That leads to us owners to discover all the fun stuff that happens with a few things just not there and no signs that it ever was there 10 years ago....
For example:
Illuminated lighter socket rings
Door puddle lights
Door interior latch handle lights (What light?)
Cover cap to the positive jump start point under the hood (snap.. oh, well...)
Pull handle for the spare tire.

Someone opens up the door panels to fix whatever and never reinstalled them. Happens all the time.

Funny you should mention the door handle light - I have that "problem" on my drivers door - the dealer fixed something in the door (before I got the car) and the LED is now dangling down inside the panel somewhere... Sheesh...

Last time they serviced the car (first time for my ownership - and the last) they broke three clips on the cabin filter cover and lost one of the acoustic cover hex bolts down under the engine - which I found when doing my own maint. later on. :rolleyes:

It's so sad that everyone has these dealer stories... :(

Uh, what screen? :doh:

Huh, don't know that I remember that being there. I suppose that holds the cap up off the tank enough to allow air in.