have 2004 z71 with 5.3 L motor, bought new, extremely well maintained. Never over 3 k miles between oil changes...Have engine clicking noise, and almost sounds like a chirp, or metal barely rubbing against metal, in flywheel area...mostly sounds like in oil pan area. Noise just started....gets a little quieter when engine warmed up...but still very noticable. Not the clatter most people complain about that sounds like lifter noise. Could it be oil pump noise, or something loose in lower crankcase ? - The ticking or chirping noise does increase on acceleration. - Need your input or ideas.