my dad owns a 2003 gmc sierra 2500HD with the LB7. the truck is bone stock; never been chipped or programed. the other day on his way to work he felt a slight vibration while accelerating to highway speed and noticed a cloud of blue smoke. needless to say he put the truck in neutral and slowed to a stop on the side of the road. after inspecting under the hood and noticed nothing out of the ordinary (just the engine running rough) he continued his way to work. we had the truck toed to a gm dealer suspecting it was the injectors causing this problem. the truck was 30 days out of warranty too when all this happened so he was quoted 5100 dollars for the repairs. the mechanic started tearing the motor apart to do the repairs when he noticed one of the valves was missing. upon removing the cylinder head this is what we found. has anyone heard of this happening? it just seems weird to me that an engine could fail like this for no apparent reason.

also too never was any knocking, banging or any other noises noted before or during, just a vibration in the truck and the engine idling rough.

my dad owns a 2003 gmc sierra 2500HD with the LB7. the truck is bone stock; never been chipped or programed. the other day on his way to work he felt a slight vibration while accelerating to highway speed and noticed a cloud of blue smoke. needless to say he put the truck in neutral and slowed to a stop on the side of the road. after inspecting under the hood and noticed nothing out of the ordinary (just the engine running rough) he continued his way to work. we had the truck toed to a gm dealer suspecting it was the injectors causing this problem. the truck was 30 days out of warranty too when all this happened so he was quoted 5100 dollars for the repairs. the mechanic started tearing the motor apart to do the repairs when he noticed one of the valves was missing. upon removing the cylinder head this is what we found. has anyone heard of this happening? it just seems weird to me that an engine could fail like this for no apparent reason.

also too never was any knocking, banging or any other noises noted before or during, just a vibration in the truck and the engine idling rough.

Damn! That's pretty impressive.

At 247K I was going down the road in my stock '01 at 65mph with a 5000# ltrailer when mine blew up about 400 miles from home. No noise or anything else.....just poof, then blue/white smoke and lots of noise as I coasted to a stop. When I restarted the engine it just poured smoke.

I knew the engine was toast so I had the truck towed home and ordered a long block from the dealer. It was about $13.5 installed out the door. About 60K miles later the new motor needed injectors that were covered under the 100K mile warranty for the new motor.

Good luck getting it going.

DANG!!!!!!!!!!!!!!!!!!

Good luck with it.

A injector failed and caused all the damage. Where is the Piston?:eek:

i suspect once the valves broke off into the engine the piston exploded into tiny pieces and is now in the oil pan. some smaller pieces may have blown out the exhaust ports out through the turbo

Wow! Shit these Duramax's are so tough they eat metal pistons for lunch! :) :) Youch!

yea so im guessing no one else has had this problem with theres yet?

i would really like to find out why this happend.

Valve stems are welded to the tips and they do break...probably a few in a million, and you're the unlucky one. It happened to a prominent member here with a brand new set of valves.

Or, the retainer broke. Either way, if the valve head got in between the piston and head, the piston loses.

Sorry about your bad luck, bad deal.

it looks to me like that the head started melting from a bad injector then the valve broke because of the heat and that the head was deformed

Holy Cow! Like nwpadmax said, the valve is a lot harder than the piston and will win that battle every time.

it looks to me like that the head started melting from a bad injector then the valve broke because of the heat and that the head was deformed

If anything melts from a bad injector, it's the piston, not the head. The head has far too much cooling for that to happen.

destruction is cool especially, out of warrany destructuon. I would think there would be some drivabililty issues prior to this happening, if it were an injector. but you gotta blame something.

It was about $13.5 installed out the door. .

wow you got taken for a ride by that dealer...I have less than half of that in my built motor...

ben

i ran into a guy once he stated that him and his father had tore down 10 or 11 duramax and neveer found out why they blew a month later mine went with the cruise set at 71mph on a slightly hilly interstate we just put in a junkyard engine miles was at 161,000 if i remember right 'yard engine had 92,000 and anything that stuck out was either bent or cracked but when all done its been a good puller

my uncle told me about years ago when he was hotshotting, his 6.2 dropped a valve, but kept trucking for his whole trip. dropped around baytown, tx. and he went to east La. and back to houston