Is it normal to get a whistling noise from the centre air vents when the fan is above 4 bars on the display, Mine makes a terrible whistling noise especially the left hand cente vent. No noise with vent shut.

It might have some debris in there like a leaf??

Somethimes i get a whistle from my vents when on high, but if you change the angle of the vents (open them up more), that usually solves it for me. To much air coming through small gap.

Mine makes a funky sort of whistle when the air con goes on :S