Engine Noise Video

[Stumpy]

I've got an engine noise which is mainly noticeable when the engine's started from cold. It's still there when it warms up but nowhere near as loud.
The noise can be heard a little when it's idling but is far more noticeable when the engine's on the overrun.
It sounds to me like a possible alternator or water pump bearing.

Any suggestions?

http://www.flickr.com/photos/graemetaylor/6832925748/in/photostream

 

[mantis946]

Mine made the same noise when the alternator was fubar