Gallardo - advice needed on hard-to-track-down noises

[stefan1]

I'd appreciate the PH Lambo wisdom on an issue with my 05 Gallardo that is driving me a bit spare. I'm used to the normal clonks and noises from the car (eg, worn anti roll bar bushes, noise from the suspension over bumps), but there is a new noise that neither I, nor my garage, can track down. It's been in to the garage twice, and most recently I drove with the engineer and it appeared to have gone, but now it's back (as is so often the way!).

Over the weekend, I did my best to really focus on when the noise starts to come in, and where it is coming from. This is what I gleaned:

- It is a clonking noise, like something heaving rattling or something knocking up against something else
- Frequency varies, but around 1 to 2 hertz
- It sounds like it is coming from the rear bulkhead, but one can never be sure
- It disappears above about 30 mph (or it can no longer be heard)
- It appears when slowing down (not necessarily braking).
- It is more evident when the car is fully hot (ie, has been driven reasonably hard) - when the car is cooler, it is less evident (so perhaps something metallic is expanding, and then knocking against something?)
- I can make the noise appear when crawling along (2-3 mph) by braking firmly - there is an immediate "clonk" in response. This seems quite repeatable, if the car is hot.

My garage have checked the suspension over twice now, tightened everything and greased everything so I am pretty confident that is not the issue. (And the anti roll bar bushes are apparently not worn.)

Any guess I can make would be pure speculation, so I was wondering if anyone had experienced anything similar, or has any suggestions before I go back to the garage for a final go at this.

Cheers

Steve

[Gring]

Dont know if this helps at all, I had similar in my Maserati. It turned out to be the tracker that had worked lose and was banging against the cars body.