A metallic "popping" or "snapping" noise - rear suspension

[mightychipster]

Hi, I've exhausted my very limited knowlege of how to resolve my situation so I would like to turn to the good people on here to help me out. Please let me explain. I purchased a 2004 BMW E46 330CI convertible that has only 49,000 on the clock. In the last few months I have experienced what I can only explain as a "popping" or "snapping" noise coming from somewhere in the rear suspension if either:

1. The cars weight shifts i.e. turning a corner or reversing onto my inclined driveway
2. When lifting the rear of the car using a jack
3. The noise comes from both the left and right hand side of the rear

I've replaced the outer upper and lower control arm bushes as well as the rear trailing arm bushes too. I've replaced the shocks and shock mounts and greased the anti roll bar bushes and control arm links. I've had the subframe checked for cracks too but the noise is still there.

Has someone got any experience or suggestions for me please?

I'll try and post either an audio or video clip if I can.

Thanks in advance

[mightychipster]

AFAIK the subframe was reinforced on the E46 at some point early 2000 and the convertible apparently has a different subframe and is not prone to the cracks of the other models / earlier versions.

[mightychipster]

Thanks for the comments so far, I'm drawn towards the possibility that the coil springs may be showing signs of failure as the root cause. Could this also be known as metal fatigue? I'm thinking springs because when you press down on the rear repeatedly I also get a creaking noise and other than the shock absorber I'm not aware of any other part that "absorbs" movement up and down. Am I right in thinking this?

A very quick search on youtube I found this video (although of a different car and spring set up) that closely matches the creaking and snapping noise, especially at the 10 second mark.

https://www.youtube.com/watch?v=FxIk5-OWfV0

[mightychipster]

So, some good news. I undone the lower bolt on both rear shock absorbers, with the car rear jacked up i then moved the rear wheels laterally in an up and down movement. Hey presto, the culprit was the anti roll bar bushings catching inside the bushings clip. Now both replaced and with a slight layer of grease the noise is gone!

Thanks for all the suggestions

MC