I have noticed for the past two years that the engine in my '93 has a light knock/chugging/pounding noise to it that I cant figure out. The sound is more pronounced at the first start of the day until it builds oil pressure. The oil pressure is 50-75 cold and 25-55 hot. I think it could be injectors because the noise gets really quiet when the engine is in overrun and the fact that these are out of another truck with 200k on them. At wot after the smoke clears, I get puff of black randomly like one could be leaking. The thrust bearing checks out ok but the cam sensor has rubbed the balancer at some point for some reason which concerns me. I think if it was an internal engine issue it would have blown up by now with me grossing 25k+ frequently. No blow by or oil consumption and it still pulls hard. What do you think?

 

Have you adjusted the valves??? I had an engine knock and I started with injectors because when I cracked the number 3 injector line loose the engine wouldn't miss, Put 5x10s in and that helped some but still had a knock,
i adjusted all the valves which was maybe .010 on the loose side on all of them, tightend them up and it took the knock away, and i gained milage.
Also before I adjusted the valves it took alot of throttle to keep it cruising at 60 and the power was awesome for a turned up pump once the turbo lit but, once i adjusted them it smoothed the power band out and cruising i dont use much throttle.

 

I'll adjust the valves and see what that does. Does turning the engine backwards with the alt throw anything off.

 

didn't seem to with mine lol... I just paid real close attention to the valves to make sure they were all the way closed.