A bad PCV breather hose can not only make a mess in your engine bay spraying oil everywhere, it can have a negative impact on your engine's performance and fuel economy. A genuine Audi part, this will be a direct replacement on 1.8T motors.
If you've got a cam chain that's rattling chances are the tensioner is on its way out. Replace your tensioner with a new OEM tensioner and quiet down the cam chain. Make sure to pickup a new valve cover gasket and tensioner gasket for the service!