Whistling at low rpm?

[KarlB1]

Hi guys
Picked up a 182 last night and have noticed 2 things.
First thing is a metallic rattling/blowing kind of sound under heavy acceleration which I think may be an exhaust leak by the manifold or the cat, shouldn't be too bad to locate.
The other is that you to 2krmp I have a Whistling kind of noise coming from the belt area? After 2k revs it's gone completely. Kind of sounds like a dodgy turbo as it spools up. Any ideas at all before I go to a local 'specialist'?

 

[Jonz]

Rattiling can be caused by the heatshield. Are you sure its a whistling noise as opposed to a whine?

 

[hsustyle]

I have a faint whistle noise up to around 2k also under gentle throttle.. Sounds like it's coming from lower front o/s area