[=C=]

Originally Posted by Jklad

It could also be warped rotors if they are worn

That's what I was thinking. Warped pads or rotors.

[Bmwfixerguy]

Originally Posted by feuer

You are missing my point. Is not that is immune to busing wear but is less prone to brake vibration due to suspension component failure, and that is due to suspension design which is completely different than previous generations.

I have to say that it's the complete opposite... The e90 shares a very similar looking and styled "lower control arm" to that of an e39 tension strut.. And of the tension strut styled cars were always notorious for wild wheel shakes under braking

E46ers had the totally different design and what put them on the map for control arm bushing wear

Back to the OP problem...
If you changed the scrub radius with wheel offset or spacers I can say for sure it's bushings...
I have always found warped rotors on clue to cars much easier at parking g lot speeds and super light pedal pressure..
Same goes for thrust arm bushings and c arm bushings.. Just slow speeds and stab the brakes...

Hope that helps and... A bent wheel can exaggerate the issue in the same way changing scrub radius can..

[feuer]

Originally Posted by Bmwfixerguy

I have to say that it's the complete opposite... The e90 shares a very similar looking and styled "lower control arm" to that of an e39 tension strut.. And of the tension strut styled cars were always notorious for wild wheel shakes under braking

E46ers had the totally different design and what put them on the map for control arm bushing wear

Back to the OP problem...
If you changed the scrub radius with wheel offset or spacers I can say for sure it's bushings...
I have always found warped rotors on clue to cars much easier at parking g lot speeds and super light pedal pressure..
Same goes for thrust arm bushings and c arm bushings.. Just slow speeds and stab the brakes...

Hope that helps and... A bent wheel can exaggerate the issue in the same way changing scrub radius can..

Since you are familiar with e39 design you know that both control arm and thrust arm are actually lower arms (unlike the e90) and that is the reason why they are failing rather prematurely causing vibrations at high speed. Not brake related certainly and not what OP is experiencing. If the bushings on these are bad vibrations would be constant. Per OP they are erratic. Same would be for bent wheel.
Now, back to the problem.