Turbo noise, Nissan mechanic didn't want a bar of it, he did explain that the turbo is close to the firewall so you can hear everything, funny that, with the windows down you can't hear it.
Got it looked at by a Diesel place, they said it has a noise that sounds "dodgy" but wanted an arm & a leg to take it out and have a look (its in a stupid place).
Still there, not getting worse or better, econo & power ok, will just leave it for now