Clickety-clack sound when going over bumps
 

I have this sound from under the car when going over bumps. I can only describe it as a clickety-clack as if one of the undershields was loose and flapping. It isn't that, as I have checked all the plastic and thermal shields and even wedged bits in there to be 110% sure.

With the windows down, it appears to be coming from the fuel-pump area, i.e. just in front of the left-rear wheel. With windows up, I can't hear it.

Neither the annual technical control nor an independent service mechanic could trace it. The previous owner fobbed me off by saying it was the rear left brake clip that was loose - I didn't believe him but thought I'd track it down soon enough. Unfortunately I haven't and it's driving me nuts.... any ideas from anyone?

2010 X5 35D

If it's a very rapid sound I describe as sounds like morse code that's usually anti sway bar link. If it's more of a thud but still rapid fire, is look into the sway bar mount itself.

I dunt remember if e70 shares the mount with the stiffening plate as does the e53 but most mechanics do not properly tighten the bolts when replacing the stiffening plate so that's often a source of problems.

If the sound is a loose shield of some type the sound will not be as reliable or consistent. Eg sometimes it will be silent on big bumps but also it will tend to repeat on bumps not dips or opposite.

If it happens on dips and bumps it's more often a suspension component.

Take an audio recording. Often somebody will have had the same problem and will recognize.