I have the same problem with my 2005 X5 (4.4). Symptoms are similar as others described (whistling noise while accelerating). Mine sounds a little like running water.

I got under my X5 looking for the evaporator drain tubes. I think I found them but they look different than other photos on this thread. Can someone verify that the mentioned valve (part number 54 10 7 070 130 x2) will work for my X5? The diameter of the rubber tubes is about 1/2".

One problem I see is on the driver side where the tip of the tube is very close (almost touching) a part (see photo). If I attach the valve to the tip, it will definitely touch that part. Not sure if that part moves or generate significant heat--which might be a problem. I might be able to cut the tube shorter to make room for the valve. Any advice?

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