Engine sounds blown-up/Other causes?

[C.K. Piquup]

A friend had me listen to the racket his new(6,500mi.)motor started making.Sounds like bearings are wiped,problem developed rapidly,within same day.The oil-pressure guage reads as usual.We removed the oil filter,opened up,and see no metal.The truck is a manual 5spd(flywheel),so it`s not a cracked flex-plate.Could air in injector-lines cause such racket?It is a dual-mass flywheel.I`ve had one fail,but nothing like this.It produced a definate clutch/trans bearing sound.Push in the clutch it went away(thought it was input-shaft bearing).Idling in neutral was the only time sound was heard,and I ran the truck many miles for a long time this way.Most of the rubber cushions were gone.We figured it would have eventually grenaded.Any suggestions on causes of such racket(not rod-knock/more like all-rod-knock or mains)would be greatly welcomed.Thanks

[markrinker]

I'd check crankshaft endplay and not run it. You might be able to replace bearings and/or crankshaft and save the block - if the problem ends up being bottom end related.

[catmandoo]

check the fuel.i had that problem years ago thought the rods came out the bottom,but had good oil press,shut it off and got looking around under the hood and decided well if it's that far gone i might as well see how far it'll get me so took off and it ran fine ,for 2 weeks then did it again so i changed inj's and week later did it again,got thinkin i had fuel from the same truck stop all 3 times,quit buying from them and no more problems.

[C.K. Piquup]

I`ll check into the fuel situation.I`m pretty convinced it`s not internal.I put new oil/filter on/in it today to listen again and be sure it had oil pressure.The pressure is right.I now believe this clatter is in the bellhousing.But to try better fuel doesn`t require engine removal,so first...Mark,I really don`t think the bearings are bad because of the good oil pressure and lack of frags in oil filter.But,as I said,all suggestions are appreciated. Thanks

[gmctd]

IIRC, a number of similar posts over the years resulted in replacing the flywheel with the later single-piece type.

[C.K. Piquup]

GMCTD,I think I`ll find the DMF(not cussing)to be the culprit,like you say.I guess it`s time to put my motor-yankin`hat on.Also,my friend is gonna need to go out back and dig up a couple more Mason jars.

[gmctd]

Be a lot easier to back the trans out and replace the DMF in-frame, imo.

[C.K. Piquup]

You know something?You`re right!Guess I hadn`t shifted my thinking from thinking the engine had problems.Time to put on my transmission/transfer-case pullin`hat.Thanks GMCTD,for keepin`me straight.