Hi my 04 impreza wrx has developed a rattle on first start up from cold and in every gear at around 4000rpm at very light load(just touching the throttle)it's a very metallic clicky noise that disappears when you accelerate abit harder.
Other than that there is no smoke,idles fine and performs normally.
I'm abit worried and any help would be great.
Oh I live in brackley so any garage recommendations would help too.
Cheers guys.

 

Heat shield perhaps?

 

Check the turbo heat shield and the one around the up pipe.

 

I'd get a mechanic to listen to that right away, just to eliminate big end knock.