Humming Noise

[Our Sam]

Quick question: My D4 (my10) is making an odd noise that even my local Independent LR specialist here in the UK can’t identify so I thought I'd reach out to you guys. The minute you pull away there is what can only be described as a distant noise that sounds like someone vacuuming with the occasional metallic rattle. It doesn’t increase with speed and stops completely when you come to a stop, if I lift off the brake it starts even before I accelerate. It also seems to get louder (at slow speed) when turn the steering wheel to the far right or left and does not happen all the time!
Any ideas before I booked it in, Independent LR specialist suggested may be a heat shield rattling...
Car drives perfectly by the way

 

[TheWidup]

I had the guts of a catalytic converter collapse on my XC90 cause something that sounds just like this - when they cut it open they found the filter had broken free and was causing the noise. It was the exact same thing you describe - noise on turns (I thought a CV was falling apart), noise off brake, no noise at idle. Never threw a code either. I'd see if it's something like that...