Re: OMC 5.7 Knocking but only when warm
sounds like it needs a tune-up
knock doesn't sound good. but a cheap mechanic's stethoscope from the auto parts store can really narrow down an area a knock comes from. There's a few hundred moving parts in that motor.
A filter cutter tool is a good idea to see what might be in the pleats of the filter.
What is the engine temp and oil pressure when it knocks?
