2007 Xterra 130k Miles Been digging and digging for answers to a knocking and ticking sound in my truck. When cold, i get a loud knock sounding like marbles on a tile floor. Goes away when engine in completely warmed up. Although, the ticking (clattering) is always there. Found a video on youtube of a guy removing the runner/swirl flaps from his intake manifold. The sound his truck was making was exactly what mine is doing. Has anyone ever heard of this ????