XSeries-forum

Hi All
I own a 2008 3.0sd and love it. I've spent a lot in it in the few months I've owned it, rear air bags, all rear suspension bushes, a steering joint, glow plugs and controller..
I'm intending on keeping it so want it right!
Anyway, it has developed a noise which is really hard to describe. At first I thought it sounded like a dead leaf fluttering in an air vent. I then quickly realised it only does it at low speed whilst gently accelerating. It's like a fluttering vibration. At first I thought it was from behind the dash but now realise it is more from the centre console area, possibly below the gear lever (uh oh!). I thought it might be the spare change in the cup holders rattling, it's that sort of noise - but it's not that.
Any ideas welcome please..
Thanks in advance.

Possibly the fan motor on its way out or something in there?...or you have a small vacuum leak at the rear of the engine

Is it only in 6th gear as that's the only gear the torque converter locks up in ? It can sound like going over a rumble strip on the road . What miles are on it as its usually only a very high miles issue ?

I've not used the car much since my post but I have removed all items from the storage under the centre arm rest to see if it was something vibrating in there or not. The noise was still present but since closing the sliding lid over the cup holders I haven't heard the noise. As the noise sounds below the gear lever this seems to make sense. It's an intermittent noise so I will keep monitoring it and report back.
Thanks for your ideas so far.
PS it's not just in top gear, more at a certain engine speed and load which must produce the required frequency to vibrate whatever it is making the noise..