I've tried a search but have been unable to find anything conclusive, so.......
I've got a 2007 335xi with approx 72,000 KM. Recently, I've noticed with the windows down that I get a loud hissing noise only from the passenger front suspension going over speed bumps, and pavement undulations at slow speeds. Please note this noise is not the regular noise of a spring compressing with load, but a rather loud hiss/whoosh.
At speed, I don't hear anything, likely due to road noise. Over larger pavement imperfections and bigger bumps, the noise is not present.
I've read this can be anything from sway bar bushings to a blown front strut. I've tried pushing down the on the passenger fender, and compression and rebound seem normal. The car also does not appear to sag on that side.
Any help is much appreciated!