08 duramax silverado lmm engine locked up after 6 mo rebuild.

[Dually681]

So i went and pulled the motor. Thinking the worst.
Mains are good. Not locked there. Pistons rods and sleeves look good from bottom. Pull the glow plugs and injectors no hydro lock looks good there.
Shine light to cam. All looks clean up there.
Pull head covers and no dropped valves. Im stumped. Only thing i can think of is timing something broke ip front and locked the motor there. Really isnt anything else i can think of.
Any suggestions. This happen to anyone here before?

 

[minerigger]

Shear a pin on the harmonic balancer?

 

[TheBac]

What year engine? What was done to it? Running and suddenly stopped or what?

 

[2004LB7]

Cp3?

 

[Dually681]

Its an 08 LMM. Think its timing set that broke and locked up.

 

[c20elephant]

I was out in Mesa yesterday at Copperhead Diesel (DangerDog on here) and his opinion on these trucks is people mis-diagnose these truck all too often and end up spending money and not fixing the problem.

I bought a LLY complete engine last year to part out, the guy I purchased it from stated his mechanic told him it was a blown engine due to an overheat situation. When I pulled the valve covers then started unbolting the rocker assemblies when I noticed several "loose" pushrods. These were bent and no evidence of a severe over heat as I was told. I sold the heads and when checked were in A-OK shape.

Not sure what to tell you Dually681 other than inspect the parts closely to find a mechanical failure otherwise it could have been an sensor issue or maybe what the other's had suggested.

BTW, what were the CEL codes prior to removal of the engine..?