Isx rocker question...

Ticking you here is probably wore out detents on engine brake rockers/ wore out elongated holes in rocker shaft. Kinda norm for EGR engine with those miles. Pretty much have to pull everything apart/ inspect, clean all oil passages and replace worn component s. Don't be surprised to find flaking cam lobes and rocker rollers. Best of luck.

 

You stated that you adjusted the valves clearances. The injector adjustment and Jake adjustment should also be performed. If you decide to tackle the injector set-up make sure you have a quality inch-lb calibrated torque wrench or you'll get things all screwed up. If the Jakes are just weak this may help. If you have no actuation at all you most likely have an electrical issue -clutch or brake switch hanging up or showing depressed in the ECM is the most common issue depending on the chassis. Does the cruise work?

Which cam has the low oil flow, injector or valve? Take a close look at the cam bearings I have seen them spin on higher mileage engines.You may have an oil flow issue to the rockers, any excessive wear? Oil pressure running normal?

 

Check intebrake rockers for wear where cap, snap ring holds piston in. They do sell tune-up kit for the intebrake rockers.

 

With oil pouring on the back 3 cylinders and not the front add to that they didn't try when you pushed the button on solenoid the rear isn't getting any oil. The supply oil is pouring out below it. Take it loose and see what's going on with it

 

When engine oil gets sooty due to egr that soot has to end up somewhere. You likely have soot deposits in the rocker shaft oil galleries blocking someone of that oil flow. It would be a good idea to take the shafts and rockers all off, mark them for position, and give everything a good thorough cleaning and ensure all those oil passages are clean and clear. Good soak in a parts cleaner over night and blow everything out real good might do the trick.