monkeyboy

I got a truck and it's knocking. On an engine that has a hydraulic flat -tappet cam. If you pull the valve cover off and idle it up to 3000rpm...... shouldn't I see some oil coming up thru the pushrods to oil the rockers? Because I'm barely getting any oil up there.
Would it be the oil pump?(the pressure gauge reads good). Or could it be a spun bearing? I kinda remember when I was in vocational schooling. My teacher said something about the cam bearings on some engines if they spin they'll cut off oil flow. Oh, by the way it's a 4.3 v6 chevy with 83000 miles. That be why I put this in gen.disscussion