Member Bill Poser, owner of a repair shop here in Montana, sent these images to me showing a couple of different 6.5 valves that were missing pieces.

Bill said: "These are the pictures of valve breakage I spoke to you about. If you notice that these appear to be two-piece structures. This is the second 6.5L engine that we have had this happen."

In a later email message I asked Bill if this was an original GM engine or if the heads were aftermarket. Again, Bill said: "The heads were original equipment from the GM factory and never been touched."

I don't remember hearing from anyone else who reported a similar problem, which is why I asked about whether the heads were OEM or aftermarket.

Poor heat treating could be a possible cause, but does anyone have an explanation?

Thanks,

Jim