[technik9195]

I know it a old tread the OP wrote that year ago but maybe it will help somebody. The knocking sound is most likely caused by worn out camshaft lobe ...take off valve cover and inspect (usually the intake rocker from my experience). On any cummins engine starting with the cm870 up to date change the Exhaust Gas Pressure sensor and Intake Manifold Press/Temp sensor every 100k or so miles they are not that expensive and they clog up quick. They won't even trip a code when they are going bad. You make the money up quick just on fuel . As for the Crank case filter just drill few holes on side and put it back in, I think cummins sells the new design No Service filters now that are empty. Start from there. Clean codes test drive the truck