mikefrost

So a friend of mine recently purchased an '01 XJ. It has a bad tap when it was cold, but prior to purchasing it the PO had warmed the engine up so we didnt know had bad it really was. I figured since it was the bad casting head it had cracked. Well I have an wrecked '00 I picked up cheap to part out so yesterday we set about starting to swap the heads. Well today when we pulled his this is what I found






Cylinders 5 and 6 had coolant pooled in them and the rest are pretty well burnt up.

I'm guessing this engine is pretty much toast?

The engine I have in my part out '00 is in great shape and runs strong. Looking like I'm going to end up swapping it in my friends, just wanted to get a few opinions here. I'm not a mechanic and know just enough to get in trouble LOL

Thanks guys

JeepDeep

Depends how long it was run like that. Bearings could be trash. Only way to know is pull the pan off to check rod bearings and then check cam bearings. If the bearings are in good shape I would clean it up and replace the head. I don't have a spare motor though.

mikefrost

Yea that's my problem. I think it would just be easier to drop the other engine in and it's got 60K less miles on it than his current one. I have a set of rod and main bearings laying around too so I could go through the current one and rebuild it. Decisions decisions..............

DFlintstone

If it was running with anything like that I would think there would be a huge cloud of steam! Also I don't remember any 'ticking" coolant leaks. Did you drain the coolant before you pulled the head? Is the oil milky like it ran with coolant, or is there coolant separated in bottom of the pan?

JeepDeep

I would go that route. Completely rebuild that motor and have a fresh 4.0 for whatever needs it.

mikefrost

There was some coolant in the oil. That's the first thing we checked and what prompted me to remove the head. I did not however drain all the coolant prior to removing the head so a good bit of whats in there is more than likely from that.

mikefrost

If we pull his engine I'm stroking it LOL

JeepDeep

Doo it!

mikefrost

DFlintstone

OK. I don't know. I doubt my bores look that new! Good luck.

BODCherokee

I think most people dont realize that there is coolant left in the head when u take it off. You have to drain the block to get it all out. it pours into the cyclinder the second you lift the head up.

wilcherkyle

What was the difficulty of head removal how long did it take what tools to use ? Would like to know thank you

BODCherokee

Its not that difficult. You need a pair of vice grips, a good ratchet set, some extensions and a torque wrench (reinstallation). drain the coolant, remove the thermostat housing and hold it out of the way. remove the intake/exhaust manifold, remove valve cover, loosen or remove the rockers and carefully pull out the rods then remove the head bolts. use 1"tape around the rear head bolt to hold it up out of the block because it wont come out due to clearance of the firewall. Then just lift the head up and forward. Keep track of where every bolt went and keep track of where the rods came out of. I used a small cardboard box to stab them into in order.

Kalali

So was the head cracked or the gasket was leaking?