E46 clonking/pinging noise from rear under lateral load

[trackdemon]

My E46 used to occasionally make a strange clunking noise from rear under load, it's become a bit worse of late (I'm on a european road trip) and I'm worried in case something is about to go bang. Only happens under lateral load, sound like something pinging into & out of place, like a suspension mounting. Car drives fine, and handles well, but wanted to garner advice in case someone knows what this is likely to be....

[e21Mark]

Diff mount seems most obvious. If you can't get it looked at soon, just try and drive with some mechanical sympathy, till you can.

[outnumbered]

I've owned an E46 M3 that did exactly this. It defeated at least five dealers/specialists, and I never found out the cause, despite a lot of suspension bits being refreshed. If you do work out it, let us know !!

[Cemesis]

Have the RTAB's been replaced?

Check the springs are 100% and have no broken coils.

Is it minor load or full on 'edge of grip' lean?

[trackdemon]

If driven gently there's no noise, but any tight corners cause it do ping, as does any high speed direction changes. You can literally feel it twang through the body; quite disturbing tbh!!

[e21Mark]

Check springs and their seats.

[wiggycerb]

I would check that all the wheel bolts are tight and also the camber adjustable bottom arm.

[RichardM5]

Check for cracks in the boot floor where the rear sub frame attaches, for an E46 M3 it's really a question of when the floor goes, not if.

[geeks]

RichardM5 said:

Check for cracks in the boot floor where the rear sub frame attaches, for an E46 M3 it's really a question of when the floor goes, not if.

This was my first thought too!