01 xj
2000-2001 XJ's had a different alloy used on the heads at cylinders 3 & 4 that is prone to cracking if the engine overheats. This is really the only major con I know of. Making sure the entire cooling system stays clean and functional will keep anything from happening in this area though. I'd recommend replacing it all just to have the knowledge that it's all new.
Some would say it's a pro, others a con, but many 01's came with the NP242 t-case rather than the NP231. Easiest way to tell which you have is to simply look at the t-case lever next to the shift lever. If you have the option of full time 4wd, you have the 242. If not, you have the 231. Full time is nice, but he 242 is a weaker t-case than the 231.
Some would say it's a pro, others a con, but many 01's came with the NP242 t-case rather than the NP231. Easiest way to tell which you have is to simply look at the t-case lever next to the shift lever. If you have the option of full time 4wd, you have the 242. If not, you have the 231. Full time is nice, but he 242 is a weaker t-case than the 231.
CF Veteran
Joined: Nov 2010
Posts: 1,140
Likes: 1
From: cape cod ma.
Year: 1998
Model: Cherokee
Engine: 4.0 i6
X2^^^ and the 2000-01s have a low pinion front end instead of the high pinion..thats only relevant if you plan on lifting it and offroading with it...great trucks
CF Veteran




Joined: Nov 2010
Posts: 5,840
Likes: 117
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
As mentioned, the "infamous" 0331 head on the 00-01 is a pretty significant con.
Will all 0331 heads crack? Absolutely not. However, this forum and all other XJ forums that I frequent are littered with threads of those that have.
I would recommend going with a 98-99 if you can find one. If you do go with an 00-01, be sure the cooling system is scrutinized CLOSELY. If there are any original parts on the cooling system, replace them. I just diagnosed a cracked 0331 head for a guy that blew a 10 year old coolant hose, resulting in the cracked head. Engine is now shot. An overheat will almost assuredly crack that head and if not caught soon enough, coolant mixes with the oil and toasts the engine bearings.
Personally, I love the 242 case. Fulltime 4WD is awfully handy when the roads are dicy. You can run the 242 in Fulltime in any road conditions, even dry pavement.
Will all 0331 heads crack? Absolutely not. However, this forum and all other XJ forums that I frequent are littered with threads of those that have.
I would recommend going with a 98-99 if you can find one. If you do go with an 00-01, be sure the cooling system is scrutinized CLOSELY. If there are any original parts on the cooling system, replace them. I just diagnosed a cracked 0331 head for a guy that blew a 10 year old coolant hose, resulting in the cracked head. Engine is now shot. An overheat will almost assuredly crack that head and if not caught soon enough, coolant mixes with the oil and toasts the engine bearings.
Personally, I love the 242 case. Fulltime 4WD is awfully handy when the roads are dicy. You can run the 242 in Fulltime in any road conditions, even dry pavement.
the low pinion and the head like every one said and the only major cons. but the front axle can be swapped easily with a high pinion dana 30. the head problem is really simple just dont let it got to hot just like with any other car.
i love my 2000 and have a hp 30 waiting for when i lift it i pick it up for $100
i love my 2000 and have a hp 30 waiting for when i lift it i pick it up for $100
Trending Topics
Newbie
Joined: Oct 2010
Posts: 12
Likes: 0
From: Virginia
Year: 2001 Sport
Model: Cherokee
Engine: 4.0 I6
I have a 2001 XJ...like everyone said, watch for the the potential 0331 cylinder head crack between cylinders 3 and 4 (coolant can usually be seen on the top of the head through the oil filler cap). My cyl. head was replaced this month with 132K miles on vehicle, Nice vehicle otherwise..
I have a 2001 XJ...like everyone said, watch for the the potential 0331 cylinder head crack between cylinders 3 and 4 (coolant can usually be seen on the top of the head through the oil filler cap). My cyl. head was replaced this month with 132K miles on vehicle, Nice vehicle otherwise..


