rav wrote:
Thanks all.
I tried the WD40 on the belts I could see (not balance or cam) and the noise goes away for a short while, but comes back again within a few minutes. I had my daughter to video this, but at 1m15s I can find no easy way to upload it to here.
I checked the tension on the belts that I had sprayed with WD40 and they seemed fine to me, if anything - perhaps a little loose?
R
IMHO I reckon you have your answer there

. However, just for insurance I would run the car without the PAS and alternator belt and see if the noise is gone. If it is happy days. The noise will always come back despite the WD-40 or Belt squeak stop, since the belt ultimately is either wrong or more likely, worn.
I have had loose aux belts on cars (my Escort was one of them; it came to me with the wrong belt) and if the belt is of good quality it should not squeal.
But, I would also check the alignment of the pulleys as Waylander pointed out.
If it's had the belts and rollers done why spend that cash to redo them again when they were never at fault? People must love burning cash. IME most garages will not change the auxiliary belts when a cambelt is except for three reasons :
[*]You ask them to do it
[*]They were noisy when the car went in
[*]The service schedule explicitly tells you to do it and there are repercussions of not following it ; The Clio 172 and 182 are a good example of this (if the aux belt breaks there is a high chance of it going into the cambelt with pretty obvious results).
My dad's Mondeo 2.5T (Volvo engine) had the cam belt changed by a specialist with the same aux belt. If I am honest, I think most of my cars were fitted with the old aux belt (Pug 306 GTi-6, Pug 106 GTi, Pug 205 GTi (previous owner), Ford Focus 1.6, Pug 306 1.9 TD, you get the idea).
On two cars I had pretty serious sounds where I thought it was game over. In most cases I was fine.