Quote Originally Posted by Peter-E36
I reckon it's gearbox or diff, could be power steering pump either. Do you have the service history? Or any record of when the oil was changed or maybe topped up in either of them? BMW have "lifetime" oil in some but it's a load of crap, what's lifetime, 10 years? 20? 100k? 200k? 700k?

Take it for a spin and put it in neutral (while driving) and if the whine goes away then it's not the gearbox / power steering pump at least
ok, I'll take a video when get home later thanks.
I'm told they serviced it just before I got it.