[ChickenFriedRice]

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!

[HP Autosport]

Originally Posted by ChickenFriedRice

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!

Sounds like the struts and shocks are working.

Have you looked for any signs of fluid leaks from the front struts or rear shocks?

[ChickenFriedRice]

No evidence of a leak but I haven't had an opportunity to jack up the car and take the wheel off.

I'm at the dealer right now and the shop foreman went on a drive with me to replicate the problem. He doesn't think it's anything major, maybe just needs the strut housing lubricated. I'll find out soon enough.

[ChickenFriedRice]

UPDATE

Both front struts were inspected and no leaks were found. They basically lubricated the front shock stoppers and left it at that. The noise is still present but told me not to worry about it.

An independent shop I called suggested lubricating the sway bar bushing and endlinks but I'm unsure if I should pursue the issue any further.