a/c damaged?
 

turn on a/c and loud rattling metal against metal scraping noise coming from engine bay....drivers side i think. only started today, was working fine yesterday.

If the AC compressor is not stuffed then It could be the electronic clutch slipping. I had this problem on a old falcon once. I hit the clutch with some degreaser spray, let it dry and I never heard from it again.

Is is like a really high pitched squeaking kind of scrape?

nah its not high pitched at all. very deep grinding.

Yeah, your AC compressor sounds fugged.

cheers mate, would this be a result of putting more power to your engine? like the compressor cant keep up and melted or something....should i upgrade to something else or just replace?

cheers,

no. AC compressor turns off when full throttle is applied and the RPMs go over 4000rpm or thereabouts.

Id say, the oil that is usually mixed in with the compressor gas is comprimised and it was not lubricating the moving parts inside the compressor

cheers for ya help, i'll to subaru and see if i can get one under warrenty.