Oily intake ports in head

Back ground info
Rebuilt HO 4.0 with approx 70000 miles

Engine has been studdering
Replaced cap, rotor, plugs, wires which needed changing
Checked map, tps, coolant temp, dist pick-up

Issue jeep has been studdering some under light load (crusing) but not all the time, and lifters/valves seem to have gotten noticeably louder in the past few weeks. So not really knowing what else to do me and my brother (graduate from wyotech automotive school) pulled the head. We noticed oily intake ports in the head. Center ports were worse. When i changed the plugs they looked a good color but was changed when missing first started.

When we rebuilt the engine from what i remember the head got new valve stem seals and normal overhaul but no new valve guides. Could the guides be worn allowing the oil to be sucked into the ports and sometimes not allowing the valve to seat fully/correctly.

I have read posts about pcv valve being clogged and all that jibberish but no sign of that being the issue.

Any ideas before i send the head to the machine shop to be checked???

Have pics? I don't think that oil leaking down the valve stem would cause the whole intake port to be covered in oil. It may just be fuel residue you are seeing.

First off, is the intake on the jeep, or is it disassembled and you are in the process of putting it back together?

I'm betting it's just dirt/fuel residue. I've seen that in alot of other engine's. Either pull the intake and clean the intake runner's and the intake ports with a tooth brush & solvant, or if you don't want to/can't clean it that way. Try seafoam.

Personally I would clean it good and see how fast it builds back up before taking it to the machine shop.

You and your brother (with his wyotech training) should be able to check out the valve guide clearance yourself. Remove the valve stem keepers and check for sideways play with a dial indicator (with the springs removed). Should be less than .003". FSM says you can knurlize the guides to repair, but many forum posts have said that this is a bad idea and nuw guides should be installed which requires machining. Keep the parts numbered or sorted so that they go back in the same place.