Truck Repair: cant find rattle, valve cummins, metal shavings

Question
i have a 1998 35000 series dodge truck with 24 valve cummins.it started to make a rattling sound{like a bolt in a coffee can,thought flywheel bolt came loose as sound was coming frombell housing area.i took rubber hose and listened to engine running and soundwas coming from down low.several people said broken flywhell.i removed tranny,all bolts were tight ,flywheel is not broke or cracked.started engine without trans or converter in place and the noise was still there again coming from low inthe engine rear area.pulled oil pan,no sign of metal shavings of any kind no loose bolts no unusal or obvious problems.pulled head to check springs and valves they to appear to be normal turbo seems to be fine as well.talk about frustration,for sucha loud noise not to be able see obvios problem,engine is now out of vehicle.im at aloss for what to do,truck has 150,000 miles and i can tell someone has bee inside engine before.do i just go ahead rebuild,buy long block also when you turned off vehicle you could hear rattle for a second after engine stopped,like a bolt in a coffee can if you spin can then stop bolt wouldroll back and fourth till it stopped,best that i can describe itwell i think ive covered it any insight would be really apppreciated,thanx for your time sincerly dan ,lost in diesel land.


Answer
I havent heard of any thing like that.If you have the pan still off,maybe check the end play in the crankshaft.A ReCon engine for a 24v engine will be ALOT.A long block would be alot cheaper probably.I would call a Cummins Distributor for both prices & then Dodge.Dodge will probably be alot higher.