[jwalker87]

Looking for ideas. My 2008 e90 335i w/ sport pkg has 117k miles and over the last 15k or so had developed a 'squeak' from the front suspension. Some research indicated it was likely the sway bar bushings or strut upper mounts; it was the typical squeak when going over uneven roads/speed bumps/etc. No big deal, it's time to refresh the suspension anyway.

Over the last few weeks I completed my suspension 'refresh' which replaced pretty much everything in the front and rear suspension. Got it back on the road yesterday and there was NO CHANGE to the squeak. Sounds exactly like it did before, which is baffling to me. Since I replaced most everything, here is what I did NOT replace:

-Coil springs
-Sway bar itself
-Sway bar bushing brackets
-Mounting hardware (nuts/bolts) other than upper strut and control arm ball joint nuts
-Strut mount reinforcement plates

My current research indicates maybe the grooves worn into the sway bar itself could be causing it, but I find it difficult to imagine that new bushings would have no effect whatsoever. That's also an expensive piece to replace for the sake of troubleshooting. I installed Bilstein B8 struts/shocks and M3 control arms, but that should be irrelevant to this discussion.

Any ideas on what else could be causing this squeak? All the discussions I've found relate back to the sway bar bushings, endlinks, strut mounts, or sometimes even the struts themselves, but that has all been replaced. Even the rubber coil spring mounting pads were replaced.

Thanks in advance.

[jwalker87]

While I'm pretty sure it's coming from the front, I suppose I should note that on the rear, I did not replace the trailing arm or the lower control arm (roll-over strut per BMW, apparently) or their bushings; the other 3 arms on the rear were replaced. #1 and #5 HERE.

And I did lubricate the sway bar bushings prior to assembly.

[avocet]

Pull your end links and test drive it. This will be give a pretty definitive answer regarding the sway bar bushings.

[feuer]

Originally Posted by avocet

Pull your end links and test drive it. This will be give a pretty definitive answer regarding the sway bar bushings.

Which probably is....