Metal to Metal Sound

Sorry, but with the lack of information there's no way to tell what the problem might be. It's like saying to a doctor "I don't feel well....what's wrong with me?"

Where is the noise, is it loud or faint, does it go away at speeds higher than 5-10 mph?

I'd take it to a mechanic who knows what he's doing and ask him to take it for a test spin. And he might not know what the source of the noise is until he puts the car on a hoist and looks underneath.