Fuel knock sound

[Andre_The_Giant]

I have a cummins cm870 that is just loud! My father bought it brand new & sold it to me used that way and it’s still that way. 19 years later she still runs. Loudness isn’t always an issue, but a skip could be. If it doesn’t skip all the time & is very hard to diagnose I would let it get worse. Eventually a leaking injector or bad whatever will show its self. Or be easier to spot out. I chased a small rattle for the first few years of owning the truck. 10yrs of owning it later it still does it from time to time. I gave up.& it thought me this lesson

if your pulling hills loaded strong, just drive the truck