funny knocking noise in 5.0L

[Denso]

hey guys, got a question for ya. my 5.0 l v8 has a knocking noise coming from the bottom of the engine. it sounds almost like a stone getting rattled around in the sump, its more prominent on idle but kinda goes away when the engine gets above 2000rpm. i cant hear it when im driving, only when im outside the car and its idling. there has been no loss of power and the engine idles and runs fine.
any help would be greatly appreciated.
cheers

[VP 5.0 BERLINA]

hey buddy if its anything like a buick 6 its probably bottom end bearings or could be your exhaust my vp 5.0l has the same noise i took it to an exhaust shop and it turned out that my exhaust was rattling against the brackets holding it cause it needs new rubbers get under it and have a look at ur exhaust first then maybey get it checked out by a mechanic

[Denso]

problem solved, it was the belts. ive never heard a belt making a knocking noise before but i guess anythings possible with a bloody holden.

[VP 5.0 BERLINA]

wow that is a new one lol at least its an easy fix lol