My '02 5.9 24v a few weeks ago while on the interstate, oil filter came loose and lost nearly all oil before i turned the key off and coasted to the shoulder. Let it cool off replaced filter and oil (wasnt showing on dipstick) started up, oil pressure still good, ran a bit rough at first then smoothed out but has a knock that sounds like on the top end. pulled valve cover nothing broke that i can see. Drove it home about 150 miles from where it happened. oil pressure great no fluxuating, power seems fine. just knocking. My question is in my experience working on big truck cummins engines ie. NTC 400 and 350 small and big cam engines, it is common to the push tubes to fill with oil and become "loaded" and thus making the engine knock very bad. This is my first thought listening to my 2nd gen. 5.9 24v. I am not at all experienced with the workings of this engine, but if the knock is something major i cant see the oil pressure being as good and steady as ever. Any thoughts?? Thanks