Hope you guys can help with this. Was having hard starting problems about 2 wks ago. Checked glow plugs and had at least 4 open. replaced them and saw the tips looked deformed, and were slightly shorter than the new ones. Thought probably due to plugs being 10 yrs old, and replaced all 8 w/AC delco 60g plugs. Lasted 2 wks and now have 4 plugs open again. Tips are same way again, the very tip is deformed and looks melted. I know glow plugs should last longer than that,especially with all that i have read about the AC Delco plugs. I have now replaced those 4, along with cleaning and/or replacing wire terminals and controller. Should I look at something else, possibly high cylinder temp from plugged cat converter?? Truck has been runnning OK, but does seem to be lacking power slightly and smoking more on hard acceleration. No PCM codes.

You were only dreaming about replacing them the first time?

Seriously, ??? WTF?

If your cat is plugging up, then gut that thing. It might not solve your problem, but it sure won't hurt.

Do you have a pyro?

no, i wasn't dreaming. i really did replace them. it is strange to me also that this would happen. No gauges right now, although that would help.
I probably will gut the cat, but i was hoping someone else may have run across this before.

Did you look at the tips B4 you installed them - the element is welded to the case at the tip.

Guess it's possible that you have 4 injectors that are squirting like blow-torches - you'd need to pull them rather quickly, have them tested B4 they do that to your pistons.

You really need an EGT and Boost gage to tell, but low power could be plugged soot trap - usually due to low Boost pressure, tho.

yes, i did see how the new ones look, but the ones i took out, the tip was not
round, and the plug was shorter than a new one, only by a little, maybe 1/8".
it looked as though the tip was melted

Correct me if I am wrong GMCTD, but if you had really advanced timing isn't that supposed to be hell on the glows?

Only high EGT's can effect the glow plug appearance, no matter what the timing setting - repeated long-duration glow for winter starting can also effect the over-heated appearance, and the burn-out event.

Also, early gp's were made by Delco and Bosch, so no comparison to the late versions, made in 3rd world countries across the globe - or Italy.