3500HD Flatbed's 6.5 snapped a timing chain

[Wildbill0088]

This is pretty weird seeing how most mechanics we have talked to have never heard of a 6.5 snapping a timing chain. Even weirder it was just sitting there idling fine then just died like it was shut off with no strange noises (at this point the thought was the FSD was acting up again) until my dad attempting to restart it which resulted in a very quick series of awful noises (of the bending metal variety) and then turning over abnormally fast and free. Got the front cover and the valve covers off and so far have a torn apart timing chain and a bunch of bent push rods. Pretty weirded out by this one cuz it's definitely not a common issue (at least around here). Anyone got any ideas? Truck/engine has 170K miles on it.

 

[outalne94z71]

actually not all that uncommon, the 6.5 chain stretches a lot and should be changed at about the 100k mark, same thing for injectors and balancer/pulley

breaking cranks and cracking the #8 cylinder are other things they are good at along with 97-2001 506 blocks cracking from the piston squirters into the water jacket

 

[Wildbill0088]

Really makes me wonder how the successor of something as reliable as the 6.2 could have all these flaws, more prove of newer not always being better I guess

 

[Horns]

There's more proof of why GM sold off the whole detroit brand and teamed up with Isuzu. I know I've said this before, but if I were in your situation I wouldn't piss around rebuilding the 6.5. Put a Cummins in her.

 

[outalne94z71]

Really makes me wonder how the successor of something as reliable as the 6.2 could have all these flaws, more prove of newer not always being better I guess

the 660 and slightly better 599 block 6.2 was not all that great either, prone to cracking the mains in the block the 6.5 problems were mostly from the penny pinchers making decisions and making the blocks cheaper and faster, there was such a demand by 97 that the blocks went right from the foundry to the machine shop with no cure time and caused stress risers along with the weakening by adding piston squirters, when gm sold the 6.5 to amg the blocks got more nickle and better building process, the new p400 is a really nice 6.5 but a bit expensive so many opt for the optimizer 6500 at about $6k