Sporadic whining noise Mondeo ST220

[cortinamarque3]

Hi
I am starting to get a really sporadic very loud whining/droning noise from the front of the car when driving at medium to low speeds. Happens when pulling off but also when in motion. It is very loud but no warning lights come on. Can't be brakes as the car is in motion when it happens- it lasts from 1 to 3 seconds. It is quite a high mileage car 150000 miles.
What on earth is that do you think?

Thanks Matt

[Zad]

Alternator? Sat in the middle of the 'V' they do rather get cooked in there. The bearings tend to sound grumbly rather than whining though.

[mybrainhurts]

I think you've got Ed Balls in the boot...

[shoehorn]

Standing at the o/s wing looking at the engine,the alternator is fitted low down on the block just above the o/s drive-shaft,behind the front wheel as such.
AC is to the right of the block(almost exact opposite position to the ALT) and the PAS pump is in the Vunder the front engine mounting.
Also check the condition of the small water pump belt and tensioner pulley at the gearbox end of the front(RH) bank of cylinders.