Originally Posted by Bmoroneymd
Broken valve spring on intake valve. Valve stayed in place so going to attempt to change them all out and hope for the best
Glad you found it. I haven't had that on a 4.2 but a trick we used to do to change a broken or weak spring was to pull the plug and feed a couple of feet of cotton clothesline down into the cylinder, then roll the crank until things tighten up. It always held the valve in place nicely so we could fix things. My luck it would be stuck but good till I messed with it and even if it couldn't fall completely down it would still make getting the new spring on a PITA. I'd put new keepers and all the rest on it while you're at it, cheap insurance.