new head gaskets, now runs rough and smokes
- Thread starter IdahoMike
- Start date
this one explains it all as far what to look for when at TDC or cylinder #4 which is what I needed to make sure I'm not out... Thanks
The GM procedure is to rotate the crank 360° back to TDC.
Like gmduramax and you said, you can just move the engine until the valve fully closes, then adjust it. That will work fine, but takes a lot longer than the GM procedure, which only needs it rotated to 2 spots.
Like gmduramax and you said, you can just move the engine until the valve fully closes, then adjust it. That will work fine, but takes a lot longer than the GM procedure, which only needs it rotated to 2 spots.
if you are on the exhaust stroke of cylinder 1, you will have a hell of alot of chatter from valve lash thats WAY too loose and even have some push rods jumping off or bending once they do come off. i doubt this is your issue
you ought to be checking compression. if that checks out, pressure test the cooling system. if thats good, you need to have the injectors tested. you have gotten crud in the injectors and they are now leaking or hanging open.
HEWY, sigh of relief, Thank You 2004LBZ, that was the explanation I needed, it was "rolling the crank 90 degrees before TDC if the rockers on #1 moved or not, if they move then you are on #4 TDC if they do not move for the 90 degree roll then you are on #1 TDC. So I did do my valves correctly. Now it's what valve lash 10,11 or 12 ?? 12 is the spec. 10, I guess would open them up a tad more and 11 would be in btwn, I have them at 10 which is what I think I'll stick with... so now to put it all back together, AGAIN!!!
when I did have it running there was no chatter which would make sense but I did find out that I indeed adjusted them correctly so now it's putting all back together. Lets see how many extra nuts and bolts I end up with this time...
I'm leaning towards a bad injector plug as they are original and been messed with a lot. The injectors were not taken apart and caps put on them as soon as I took off the cap so not to get crud in them, been down that road with a tractor.
an injector plug will not cause this issue you are having. it will either fire or not and then throw a code when it doesnt fire.
I lost MPG when I adjusted my LB7 to 10. restored MPG when I put it back to 12. I'm guessing when the engine warms up the push rod was expanding and there was not enough room in the lash and maybe the valve wasn't closing tight. not sure but I would stick to 11 or 12 which is what most have done successfully. not too many who have taken them to 10
In theory, no. I usually roll it so that I'm tightening the crank bolt, so I don't have to worry about me yanking on the gear wrench too hard LOL
went with 12I always set them to 11-12 thousandths. 11 runs a tiny bit quieter (or in my head it does), never had any problems with 12. If in doubt, go with 12, no point experimenting until you sort out the root issue.
good idea... I stayed with CW, rolled it several and rechecked them, all is good.
Always roll in the direction it runs. If that balancer bolt comes loose it either wasn’t tight enough or your engine/trans is way too tight.
I replaced the Bent connecting rod, the piston, all the rod bearings, and rod bolts. Reused the rings that were on the original piston as the end gap was still on the low side of the book tolerance. That was at about 163k.