Hey guys, hope someone can help me out here.I have this noise coming from my engine and its not the normal tick tick noise most of us have. I guess the best way to describe is, more like a chatter noise, like a bunch of metal lightly hitting against each other. It does it most of the time at start up, then sometimes it will do it once its warm up, just not as bad and only hear it at idle. It does it with the smarty on and when I put it back to stock. The oil level is fine, truck don't smoke, fuel mileage is great and no lost of power. There's no fuel leaks and my fuel filter is new. Anyone have any ideas? Thanks