RangerRob's video shows the exact "rattle" I'm talking about- listen when he revs and lets off, right before it gets back down to idle. Mine does that too, but do you hear the "putt putt putt putt" noise when it's idling? When I go WOT it sounds just like that, but 10 times louder and faster (with the RPMs, of course). Maddening.