I've had this engine apart more times than I'd like to think about...
Here's my situation:
I've been chasing a tick for a while on the LB7. I originally found Cylinder 2 to be ticking. So I decided to replace the 4 injectors on that side to save me the work. Put it back together, the noise is less, however it's still audibly ticking and driving me crazy (linked directly to RPM, doesn't change at full throttle, etc.) I just went outside and hooked the tech2 to it and if I cut out CYL 2 the tick that I'm chasing goes away. So it's reasonably safe to assume it's linked to CYL 2.
It is not noticeable on idle or on deceleration but on throttle it ticks like a madman solid through the RPM range no matter the throttle position as long as it's accelerating. I have replaced all 8 injectors within the year, and have adjusted the valves (I MAY have adjusted them improperly but it's hard to say for sure I guess without opening it up (again, this is like 7 times I've had this thing apart).
Here's the details:
LB7 - 350,000KM
8 New Injectors
New Headgasket and studs in January of this year
Bent a rod when I did the HG job on cyl 5 and replaced that (messed up my valve adjustment)
If/when I tear this thing apart again what should I be looking for that could possibly cause a RPM-related tick specific to CYL 2 that only ticks when it's under acceleration/load.
Okay - so an update:
Tore it all apart today, the valves for #2 seem to be all good but I readjusted them to be sure. I think I'm going to pull the injectors and put new coppers on them as well as new gaskets. The only thing I've noticed is that the injector is an injector that I replaced the solenoid on. (It's a new unit, but I broke one of the solenoid studs off the injector when I was originally installing them (they have less than 10k on them).
This ticking is constant through all RPMs and seems to be better when #2 is disabled. The engine runs poorly when I disable #2, but the sound goes away.
Is there anything else I can be checking? I may move the possible bad injector to #4 and run it with covers off to see if it follows but somehow I'm doubting it will change anything.
2001 Chevrolet Silverado 2500HD - LB7 with 217k miles - Lift pump otherwise stock