Best model year for XJ?
CF Veteran
Joined: Jul 2013
Posts: 7,554
Likes: 17
From: Monett, MO.
Year: 1999
Model: Cherokee
Engine: 4.0
Not quite, the 1999's had the very best of the old intake improvement for one with all the other new ones without any of the problems. A problem many do not think of is the Low Pinion D30, twice as many O2 sensors in the 00/01's where all up to the 99's had one O2 and the high pinion D30, stronger, more clearance and much easier if you plan on a lift to contend with.
The head was not the only problem they changed in 00/01 quite a few things before dropping the XJ line.
The head was not the only problem they changed in 00/01 quite a few things before dropping the XJ line.
Member
Joined: May 2010
Posts: 235
Likes: 13
Model: Cherokee
Re: 00-01 4.0 heads
The possibly defective heads in question have the casting number 0331. If you remove your valve cover the number should be located mid way down from the front on the left. Some heads were replaced either under warranty or later. Heads with a casting number different from that above are more than likely ok. Later, Jeep switched manufacturers and those replacement heads should have the letters TUPY.
For more info:
From the home page here at CF go to: How To's - Jeep Cherokee XJ 1997-2001 - Engine and Powertrain - Engine - Cracked Cylinder Head information. There is an informative article on this specific issue and possible solutions.
For more info:
From the home page here at CF go to: How To's - Jeep Cherokee XJ 1997-2001 - Engine and Powertrain - Engine - Cracked Cylinder Head information. There is an informative article on this specific issue and possible solutions.
Last edited by jpk; Dec 20, 2016 at 07:48 AM.
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
The possibly defective heads in question have the casting number 0331. If you remove your valve cover the number should be located mid way down from the front on the left. Some heads were replaced either under warranty or later. Heads with a casting number different from that above are more than likely ok. Later, Jeep switched manufacturers and those replacement heads should have the letters TUPY.
For more info:
From the home page here at CF go to: How To's - Jeep Cherokee XJ 1997-2001 - Engine and Powertrain - Engine - Cracked Cylinder Head information. There is an informative article on this specific issue and possible solutions.
For more info:
From the home page here at CF go to: How To's - Jeep Cherokee XJ 1997-2001 - Engine and Powertrain - Engine - Cracked Cylinder Head information. There is an informative article on this specific issue and possible solutions.
Member
Joined: May 2010
Posts: 235
Likes: 13
Model: Cherokee
Sorry about that. When I looked at the photo it appeared the number was under the cover. My bad, but now people know and the article gives a lot of info regarding the issues with the head along with possible remedies.
Also for those with a 99 XJ. It is possible you may have a defective head as well as stated in the article. The switch to the new head was done late in the 99 production run. If yours was a late build, check your head casting number. You can also get a build sheet for your XJ for free from FCA through their customer service contact service. It will list all the options your XJ had from the factory as well as the build date.
Also for those with a 99 XJ. It is possible you may have a defective head as well as stated in the article. The switch to the new head was done late in the 99 production run. If yours was a late build, check your head casting number. You can also get a build sheet for your XJ for free from FCA through their customer service contact service. It will list all the options your XJ had from the factory as well as the build date.
Senior Member
Joined: Aug 2011
Posts: 604
Likes: 1
From: California
Year: 1990
Model: Cherokee
Engine: 4.0 i6
Another resurrection of an old thread; as a new owner of an 89 Ltd that was sold in and lived in central California please explain how I use the OBD1 you speak of? I was under the (mistaken?) impression the OBD1 came in 1994 in CA.
As far as the 4.0 HO goes, it's my understanding that while the HO gains about 15 BHP, peak torque is raised to 3500(?) rpm while the non-HO models hit peak TQ @ 2000 rpm (all figures +/-). I prefer the latter with the flatter TQ curve.
As far as the 4.0 HO goes, it's my understanding that while the HO gains about 15 BHP, peak torque is raised to 3500(?) rpm while the non-HO models hit peak TQ @ 2000 rpm (all figures +/-). I prefer the latter with the flatter TQ curve.
CF Veteran
Joined: Apr 2014
Posts: 1,379
Likes: 127
Year: 1989
Model: Cherokee (XJ)
Engine: 4.0
Another resurrection of an old thread; as a new owner of an 89 Ltd that was sold in and lived in central California please explain how I use the OBD1 you speak of? I was under the (mistaken?) impression the OBD1 came in 1994 in CA.
As far as the 4.0 HO goes, it's my understanding that while the HO gains about 15 BHP, peak torque is raised to 3500(?) rpm while the non-HO models hit peak TQ @ 2000 rpm (all figures +/-). I prefer the latter with the flatter TQ curve.
As far as the 4.0 HO goes, it's my understanding that while the HO gains about 15 BHP, peak torque is raised to 3500(?) rpm while the non-HO models hit peak TQ @ 2000 rpm (all figures +/-). I prefer the latter with the flatter TQ curve.
There are not "codes" to pull. You have to go at it with either a special tool or a multi meter. do a search for "crusier's renix tips" and you'll get a TON of renix info, more than you'll be able to take in.
Also look on youtube for "nick in time films" he's made a custom renix engine management tool that is super slick and he is not charging much for it.
Newbie
Joined: Jun 2017
Posts: 11
Likes: 0
Model: Cherokee
New here guys, and new to Cherokees. Have some experience with my pop's 1963 J300 and FJ40's quite a few years ago...
Woke-up this morning thinking that it's time to pick-up an "old" Cherokee. I found this thread, which has been helpful, so thanks everyone.
Later I plan to see these two:
1998 Jeep Grand Cherokee Limited
1999 Jeep Grand Cherokee Laredo
They are darn near the same price and mileage, so none of that is a factor...
The '98 Limited is a 5.9 liter, apparently the only year with that option? Sort of neat and all, but how is sourcing parts?
Any input on notable differences between these two options would be greatly appreciated. Thanks much.
EDIT / ADD: If there are any particular areas to inspect for rust, or other problem points, kindly let me know.
Just noticed that the '99 is the venerable inline six. Read some reviews on the Limited with the 5.9 liter and between it drinking premium and being a guzzler, fueling it is quite expensive...
Thank you.
Woke-up this morning thinking that it's time to pick-up an "old" Cherokee. I found this thread, which has been helpful, so thanks everyone.
Later I plan to see these two:
1998 Jeep Grand Cherokee Limited
1999 Jeep Grand Cherokee Laredo
They are darn near the same price and mileage, so none of that is a factor...
The '98 Limited is a 5.9 liter, apparently the only year with that option? Sort of neat and all, but how is sourcing parts?
Any input on notable differences between these two options would be greatly appreciated. Thanks much.
EDIT / ADD: If there are any particular areas to inspect for rust, or other problem points, kindly let me know.
Just noticed that the '99 is the venerable inline six. Read some reviews on the Limited with the 5.9 liter and between it drinking premium and being a guzzler, fueling it is quite expensive...
Thank you.
Last edited by TonyBJ300; Jun 1, 2017 at 05:48 PM.
Member
Joined: May 2010
Posts: 235
Likes: 13
Model: Cherokee
Tony, indeed the 5.9 was the only year for that motor with that body ZJ, also, it was the last year of that body. It depends a lot on what you can spend on fuel, the comparative condition of the vehicles, option packages. I know the 5.9 was pretty much the high end ZJ. The WJ Laredo is the mid tier line. I like the durability of the 4.0L. If it was an optioned out Laredo I would go with that. The 5.9 is temping though if it is in pretty good shape. They may tend to have been run a little more aggressively because of that motor. It was sort of the SRT8 of that time. Other's may have more to offer.
Newbie
Joined: Jun 2017
Posts: 11
Likes: 0
Model: Cherokee
Tony, indeed the 5.9 was the only year for that motor with that body ZJ, also, it was the last year of that body. It depends a lot on what you can spend on fuel, the comparative condition of the vehicles, option packages. I know the 5.9 was pretty much the high end ZJ. The WJ Laredo is the mid tier line. I like the durability of the 4.0L. If it was an optioned out Laredo I would go with that. The 5.9 is temping though if it is in pretty good shape. They may tend to have been run a little more aggressively because of that motor. It was sort of the SRT8 of that time. Other's may have more to offer.
Yup, a ZJ, my bad. Was out looking at Cherokee's and Grands, and I guess got them mixed-up.
After MUCH reading, I'll want to go with a 4.0, for a few reasons. Saw one yesterday, a '98, original owner, very good maintenance records too. I passed for reasons described in a thread a few down...
Thanks again.
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