Guy's I,ve noticed an intermittent noise from under the hood the past couple of day's. It sounds horrible, and seems to be getting worse. The noise appears to be coming from the left side of the engine and perhaps also from the rear. At first I thought something was loose and was just rattling around, but like I said it's getting louder, now I'm not sure what it is. I can still hear the fuel injectors ticking so it's not that, It almost sounds like something metal is flying around inside the engine. Any advice would be appreciated. Thanks!