HELP strange noise

[dirtydenz]

I have 04 reg leon 130 tdi and its developed a strange noise when you brake or set off forward or in reverse. The noise is like a cracking sound and sounds quite substantial. It comes from the passenger foot well sort of area. Its got the dealership baffled. They've fitted a new wheel bearing and ball joint. The subframe and all the suspension has been off and been greased up on all the bushes and mountings. They've also fitted a new door hinge because they thought that might be the problem. The car has been sent to the body shop too so it could be checked for the body flexing in anyway. Any work that has been done has not affected the noise its still there.
Its hard to descride the noise other than a cracking. Its not a knock or a bang.
It's been suggested that maybe a spot weld on the chassis or something like that.
Has anyone got any suggestions or experienced anything similar.

The dealership say they have exhausted their means so it needs to go to the technical department in Milton Keens. But they are dragging their feet and its really beggining to do my head in.

 

[muddyboots]

The Rover 200 I had before my Ibiza did *exactly* the same, and we never got to the bottom of it.
I'd hear a substantial, loud "crack" as soon as I started moving off from standstill, but as the car was out of warranty I never got any further investigating it, it always worried me though.

I reckon it was one of the following:
1) Fuel moving about when moving from standstill, making the tank creak on it's rubber mounting straps, or
2) Chassis movement, like a failed weld (as you've suggested).

It was very odd though, would do it even with the most gentle movement away from standstill.

 

[craig-pd130]

I had a Mondeo that did this. Turned out it to be the driver's side front suspension coil spring. It was moving very slightly when it became unloaded (i.e. when moving from rest), and was hitting the spring "pan" at the top of the strut.

The metal / metal contact from this sounded literally like someone hitting the front wing with a ball-peen hammer. It was actually worse INSIDE the car than it sounded outside because it reverberated around the shell.

 

[dirtydenz]

Thanks guys. When i finally get it back i'll look into the coil spring idea. THanks for the comments.
Mark