320i problem

[manesh.mathew]

i bought a 2007 320i exclusive a couple of months ago. i had the problem a hissing /whining sund coming from the air vents or somewhere there even when no fan or aircon working. i took it BMW and they changed the aircon suction pump . it is quieter now but still there is a sound and seems to me it varies with acceleration as well. i check the sound of the engine engine sounds fine no funny sound . can any one tell me what the problem is . i have admit it is not a big sound u have to concentrate well to hear that .

 

[freerider]

Turn the radio up a bit :dunno:

 

[manesh.mathew]

Turn the radio up a bit :dunno:

ya thats what i am doing ....and you dont need to turn up that high as well ...but still would like to know hwat it is