I have a 2000 XJ with the 4.0. It is approaching 200k and has been great. Recently I started losing coolant. No puddles in the garage. I noticed excessive steaming during the cold weather. I checked the oil, yep I had water in it. Crap. I bit the bullet and pulled the top half of my motor off and went after the head gasket. Nothing obvious that I could tell but the amount of water that was in the crank case was pretty amazing. I checked the head to make sure it wasn't warped, replaced my valve seals and put it all back together. Did a tune up and it cranked right up. Right off the bat, the steaming was gone, the coolant smell was gone and the oil stayed clean for the first couple weeks. I checked the coolant again recently to make sure I was still alright and it was down. I added some more and a week later, it was down again. Still no puddles in the garage. I get a faint smell of coolant occasionally when i shut the engine off and get out of the jeep. I cannot figure out where it is going. Any ideas?

 

You have an 0331 head... its cracked. Probably between 3 and 4 cylinder. Even if you cant see it.

Easiest swap will be an aftermarket 0331 head or another 0331 head from '03 or newer.

Check here, http://www.partshotlines.com/ I got an '05 head that was amazingly clean with only 64k on it for $187 shipped.

the correct 0331 head you need if you go with a factory one will be stamped TUPY ander the valve cover somewhere

 

have system pressure checked do radiator cap also them go from there...

 

had the exact same problem on my 99 xj last summer. I was using a gallon of coolant a week. Try replacing the radiator cap, if the seal is worn out, the coolant can boil off. that was my problem. Hope this helps!

 

I did the radiator cap when I did the tune up. I will have to check the head. I was worried that may have been the case. Just bumps up the rebuild higher on the list I guess.

I am hoping to pick up a 99 or earlier 4.0 to build and put in here. So if anyone has one they are looking to unload cheap in Michigan. Let me know.

 

pressure check the system and cap this is where checking the head