Mysterious Squeaky Noise Coming From Bonnet

I've got a Fiat Punto 02 with about 45k on the clock. Generally been very impressed with the car.
Recently however its developed a strange squeak or whirr coming from under the bonnet. This happens intermittently, is generally quite soft and only when it's in gear and travelling above 30mph.
Have taken it to a friendly local garage who've looked at it a couple of times but can't pinpoint the fault as they can't re-create the same noise when it's stationary. They seem to think it's not the clutch or engine though.
Any thoughts or suggestions? Is it worth taking it to a FIAT dealer instead?
Cheers.

Does it sound more like a high pitched whining noise? Does it only happen when the car is cold by anychance?

Yeah, it does whine, and can be high pitched, but sometimes sounds like metal rubbing against each other. Does tend to occur more often when car is cold. What do you reckon it is?

Budgie


Is it a whine/whistle type noise as there is a service news for wind noise through the front grille.

I aint sure about the metal to metal noise? But theres a common problem with the puntos, high pitched whining when car is cold, once engines upto temperature noise will disappear, it may be coming from your cambelt tensioner, your car is on 45k so the cambelt and tensioner will need replaced either now if its an 8v or on 50k if its a 16v, then see if this fixes your noise problem.

The MK2 02 dont have front grilles..

it could be the engine

Sorry your correct,didn't notice it was a 02 plate.My 'whistles' around 40mph so I whistle aswell......stereo

Thanks for all the responses.
Think I'll have to look at Cambelt and Tensioner, cheers Punto Power .
It's the 8V and so these probably do need replacing ... could do without the the expense though! Guess it's gonna be a few hundred eh ...