Bad exhaust valve LB7

[sgoodhope]

Hello, I am new here. I joind after my 03 Crew LB7 started to blow lots of smoke & detonate. I followed advise that was given in the threds and took the truck into the dealer ship on the goodfaith injector policy. After the truck had been diagnosted with high return #'s running 44ml on the right and 61ml on the left. They decided to change the injectors. This had been the best news I had gotting all month. A few day's later I recived a call from the dealer saying to come down at 4:00 and pick it up. They were just finishing up. I went to the dealership and found a tec doing a compresstion test on the truck. I was informed that at some time a valve on # 3 cylinder had ether bent or had burnt out. I now need to know what are the torqe specs and the order to tighten the head. Also is there some kind of new fangled tool to compress the valve spring or dose a regular spring compressor work. Any words of wisdom are welcome at this point. We will just say this guy can't afford to waist anymore time and has no money to pay a dealership to do the work.

[dr.olds]

:cool:I feel you pain, A valve spring compresser will work just fine to remove the valves, Im replacing head gaskets on my 02 lb7 as we speak, are you going to do the work your self? its really not that bad, just time consuming!

[sgoodhope]

I am doing it myself. I have the valve covers off and the return line. I spoke to another tec at a different shop he is saying to pull the injector and make sure it was seated properly before pulling the head. He was saying he feels it is highly unlikely that it is actually a valve??? I have some mechanicle back ground but I would never claim to be a tec. Any input or words of wisdom welcome.

[dr.olds]

:cool:I miss understood, thaught it was already determined it was a valve, when i started having probs. with mine, pulling the inj. is where i started. they will pull out pretty easy, just pry straight up on them, before we go any further, is your motor an Lb7? let me know, we can work to gether on this, already been down this road! will be back on line this evening about 6:oo pm

[dr.olds]

if i would just read i would see it is an LB7 (been a long day!) So here we go, you may have to modify a flat tip screw driver, or some thing with a 90 degree bend in it to get underneith the injector, gentley pry straight up on the inj. may have to twist a little on it. it will come up, be very carefull not to damage or break the studs the wires conect to, as they are part of the inj. LB7 motors are the only Dmax, (that i know of) that have inj. sleaves, not a very good designe, but they had to start some where! the tool you need to pull the inj. sleaves is a Kentmore # J45910. I bought mine from the local parts house for $200 and some change, took about a month to get it, and it works like a charm. when you reseal the cups you can use RED Loctite, its the equivalant to the same stuff GM uses. the inj. hold down clamp torques to 37FT pounds, All the seals for this job are about $200 bills also. 8 inj. seals, 16 inj. sleave seals, 8 copper washers. can get part #'s if needed. hope this helps:cool:

[sgoodhope]

Hello again, I now have the head off and its a lot worse then expected. The piston is torched and one of the exhaust valves is toast. Pluse the valve is inset into the head at least an 8th of an inch. Pluse the aluminum is cooked out in a spot and there is debris scored accros the face of the head. And the cylinder wall is scored as well. No wonder GM didn't want to go any further on this one.

[Big Green]

Sounds like a bad injector to me.

A leaking injector will do just what you've described.

[dr.olds]

dude, sorry to hear that, sounds like your gona have to open up another can of worms! i have done some reserch on used LB7 motors, price range seems to be around $3500. heres the the catch, most of them are in burnt trucks, roll the dice, or rebuild yours! any question on your heads, contact Guy Tripp @ SoCal Diesel, he is the durmax Guru! any thing i can do to help ya out just let me know!