High pitched buzzing/whirring noise

[Chri5]

Yesterday I noticed my engine started making a high pitched buzzing/whirring noise which increases with engine speed. No idea what it is but it sounds as though its coming from the belt side of the engine where all the pulleys are.

Could it be bearings in alternator/PAS/aircon pump? Cam belt and aux belt kits were done 20k~ ago and have been faultless.

My PAS sometimes makes a light whine when its under load (2nd gear round a long corner for example) but it sounds completely seperate to this noise, and has been like it for some time.

Any ideas? Paranoid now

EDIT: Forgot to post the video up......

http://www.youtube.com/watch?v=n5v7GGsFR_A

 

[Chri5]

Anyone?

 

[geordie]

I would try the lower alternator idler mate

 

[realnumber 1]

Sounds the same as my mates the other week...
Turned out to be the tensioners.

http://www.cliosport.net/forum/show...ange-whining-noise-after-new-alternator-(172)

 

[Chri5]

Balls! I hope its not, that tensioner is about £110 alone Plus it was changed for a brand new genuine one only 20k ago.

Its such a pain to get to it all to check things but I dont want something going and taking the cam belt with it :S

 

[Chri5]

Hmmm, well just whipped the aux belt off (fun job that was!) and briefly ran the engine, and sure enough the buzz has gone away, so that rules out the cam belt side of things (yay!)

But trying to work out which pulley/pump is at fault is kinda difficult. The only slight discrepencies is that the PAS pump makes a little knock/tappy noise when the pulley is rocked back and forth with finger tips quickly (I'll put a vid up later to show what I mean) and that the metal idler under the air con pump can be slightly rocked inwards and outwards.....imagine if you're checking wheel bearings with the wheel off the ground to get an idea. Is this normal? its not major just slight but I cant see how either would really make the whine it had.

Tensioner feels alright and it smooth in its operation as are the other pumps and alternator but its hard to tell when you can only spin it by hand.

Thoughts?

 

[Chri5]

PAS pump shaft also seems to move in and out of the pump a little when pulled. I'll vid this too....

 

[realnumber 1]

Balls! I hope its not, that tensioner is about £110 alone Plus it was changed for a brand new genuine one only 20k ago.

Its such a pain to get to it all to check things but I dont want something going and taking the cam belt with it :S

It cost my mate £160 to have a full Aux kit fitted with new pulleys/tensioners/belt so shouldn't be that bad.