Unidentified rattle

[NO2]

My 2007 TDCI has developed a rattle that can't be identified. It sounds a bit like an exhaust burble, constant but slightly erratic. Noticeable from 30km and raises in pitch slightly at around 80km hr and sounds fairly consistent. Volume is around the same as wind noise, and close to the same pitch. At this point:
It is not tyre noise.
It is not bearing noise or CV joints.
Not loose discs (Still there under braking)
Not clutch (Clutch in makes no difference)

Conclusions reached by Ford guy and myself. He is unable to ascertain what it is as he hasn't heard the noise before. His conclusion is that the covers on the wheel nuts are rattling. Feasible ,possibly. So I am throwing it to Focii owners if they experience noise from the wheel nut covers being loose. Also any other suggestions or areas to check on the noise would be appreciated.

[marg99]

My LT TDCI has mags as standard so no wheel covers. Could be a loose baffle in a muffler they present more at idle than under throttle.

[Turbodiesel]

What area of the car is it coming from? Inside or outside?

I've had a loose heatshield under the car that was catching the wind at 100km/h.

[NO2]

Originally Posted by marg99

My LT TDCI has mags as standard so no wheel covers. Could be a loose baffle in a muffler they present more at idle than under throttle.

Mine has mags too, the wheel nuts have a chromed cover that can come loose on the wheel nut when a rattle gun is used to remove the wheel.

The noise is outside. The Ford mechanic was bouncing around in the car trying to pinpoint front or back and which side. I have been going over the car taping everything that can be jiggled bounced. The heat shield, exhaust were all checked when it was on the hoist.
Curiouser and curiouser.

[prlamb]

Was this ever resolved as it sounds like my problem.

Cheers.

[leakey]

Hmmm, I'm guessing your catylitic converter honey combe has cracked a bit off, or it has cracked in half....