hmmm.. What if the tensioner was too tight on the new auxilery belt? Not 100% like, but when I did my cam belt, it was slightly too tight, and made a slight whirring noise under load. Don't take my word for it, just a suggestion.

I know I just copied the answer, although I do agree with it. Give this a try, as its free to test, then try looking for other answers

[Edited on 29-01-2010 by Generation]

yes mate i have just been told the same thing on another site so i will get the garage tomorrow and get them to take it off, see if that is problem, only thing is though, from what i have read up about problems with them, they tend to make more of a rattle, when the noise i get is not a rattle, its more of a humming like a wheel going round with a flat tyre, would the heat shield make a noise like that?? cheers

Sounds like heatshield from under the car too me

1.6 sport, just had a full service, new rear wheel bearing, auxillary belt and tensior, its costing me a shed load to find out what this shitty noise is lol

What engine is it? My car had a similar sound and that turned out to be the timing chain which can be costly. Although not 100%.

This noise appears to be beneath the car, in between the front seats, towards engine bay area and the only way i can describe it is like a humming and continual whirring sound, it mainly occurs when for example I am going along a road at 50, il let my foot off the accelerator and roll to the roundabout im approaching then it will make the noise, its like a va voom va voom va voom (if that makes sense) I have checked all the tyres, just had new auxillary belt and tensioner put on and also had new rear wheel bearing put in, and the rest checked, and also has a full service. This noise is seriously pissing me off now and is costing me a shed load to find out what it is. Does anyone know what it could be??? Cheers in advance :)