Alright, I bought a '95 Cherokee 4.0 straight 6 under the impression it just had a bad head gasket. The person I bought it from told me it had started to overheat and so they just pulled over, let it cool and got it home. When I looked at it, it would run-albeit rough as hell and you had to keep pushing the gas pedal down. I took the bait, got it towed to my place and cracked into it. It had the lovely chocolate milk for oil, looks like a newer radiator, water pump and thermostat housing so i guess they tried to get it to stop overheating. Took the head off, gasket was fine. The intake gasket was however cracked, my assumption is that's the culprit for the coolant in oil. I went through and pulled all the valves and it was obvious they weren't seating correctly, so much carbon build up on both intake and exhaust valves & chambers. I gave the head a good cleaning and took a shot a lapping the valves, now I've run into tight valve guides on cylinders 3 & 4. Valves do not seem bent, and I'm not sure how to go about checking the guides. I was concerned about a valve lash but everything has been dismantled now so I'm not sure how to check for it, its hydraulic lifters so that doesn't really apply but I'm just not sure if there was any play on the push rods. I really don't think the head is warped but something has got this poor jeep running hot and burning rich. I'm wondering if I need to try new valves or just get another head all together. Really at an impass at this point. Any suggestions or comments would be very helpful and welcomed!!! Thanks y'all

Update: it's seeming like the valve guides on the two intake valves are tight, valves will slide in and out of other guides no problem (just to test) but any valve in those two guides binds up right at the tip. Is a valve guide job worth it or is that indicative of internal warping? Trying to get a second opinion from a machine shop and I'm thinking about picking up a cheap used head as well. Really trying to figure out the problem either way.

 

It's a crap shoot at this point. Take the head to your local machine shop and tell them your story. See what they say.

What do the cylinders look like?

 

They cylinders look fine, signs of a little moisture in cylinder 5 and the slightest nick on the piston in cylinder 3 but no valves were bent. Planning to see if the machine shop will do the valve guides, and I'm picking up another head just in case. Thanks for the reply!

 

Is the head have 0331 between the 3rd and 4th cylinder valves or in the middle on the right side of the head? If so have them check for a cracked head right there.

 

0331 for that casting number? It's a 7120.

 

Any advice on reaming a valve guide at home? 😅