and generally aren't fans of duramax forum.
Down pipe rattling?
cracked flexplate?
thanks guys! first thing i did was tune it back down to stock. no change in sound. i will have balance rates checked tomorrow. you know the cracked flex plate doen't sound that far fetched. the noise is loudest under truck where engine and tranny meet. maybe the injector issue is just echoing through the exhaust or maybe its the flywheel. but if it was the flywheel would it stop rattling after 1000 rpms? the rattle is perfectly timed and consistent with the rpms.
wouldn't an exhaust leak get worse with more rpms? it completely goes away after 1000rpms....and whats the rattle that happens when i shut it off?.....Sounds like an exhaust leak to me.