As above,the noise started bout 6 weeks ago and is very slowly getting louder.the best way I can explain it is like a metal fan like sound only in low rev range.iv checked all aux belt pulleys for any play to no avail.
The noise is more noticeable when engine is under load,I'm thinking bearings on 1 of the pulleys but like I said there isn't any play so I'm a bit stumped.
Any help would be great and cheers for the heads up in advance

Is the noise present with the air-conditioning switched off?

It is yes,thanks for reply

STRANGE NOISE FIXED.
Turns out it was the aux belt tensioner.
Like I said in earlier post on happened when under load,I had checked all pulleys for play and there wasn't any.
So i check the pulley bearing another way by getting a long screw driver and put the drive end on each pulley and my ear on the handle end and then you can hear what's happening with each assembly