Whining noise

[No.No.No]

Guys help!
There is a constant whining squeaking noise after starting up(sometimes right away, sometimes after warming up).
Vigorous acceleration seems to make it go away but then comes back after letting go of accelerator. Gets worse when air-conditioning is activated.
Parts changed so far: Both belts, ball bearings on pulleys, water pump.
Running out of ideas.. Doesn't affect performance in any way but is just really annoying!

 

[John_D]

Might sound silly but check that the front exhaust pipe heat shield welds haven't given way and the shield is rubbing on the pipe. Also the centre aluminium heat shield that sits over the exhaust can come unfixed and drop onto the pipe and make similar strange noises. This happened to my K12 and like yours putting the aircon on, lowering the tickover just enough to alter the resonant frequency of the ally shield caused it to make a rattly squeaky noise that initially convinced me that the aircon compressor clutch bearings had collapsed. Fortunately found the loose rear shield a day or two later and pushed it back onto the location studs that stick down from the floor and fitted new retention clips........