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98 vs 99 XJ differences

SurplusFan98

NAXJA Forum User
Location
LA
Hi all,


I have a 98 parts jeep and I'm looking at potentially buying a 99 that needs some of those parts. Can anyone comment on or link me to the differences in those year models? The 99 I'm looking at is the pre-coil pack version of the 4.0, but I know it has the better intake. The differences I know of are:



Intake is different
roof racks are different, but I believe compatible
computer is different I think (but idk why)
interior may be slightly different


Other than that I'm not too sure. I'm not super concerned about the cosmetic differences, but I would prefer that the engines and electronics were compatible. If that's not so, I'd love to know before I spent the money.


Thanks!
 
98 and 99 are for all practical purposes identical, and everything will interchange.
 
Unless changed by a shop or previous owner, all 98 and 99 have the 0630 cylinder head.

The distributor-less coil on plug ignition that was introduced for the 2000 model year was paired with the 0331 cylinder head.
 
That has been alleged, but never proven. Vehicles are built months and months ahead of sale, so it is possible for a 2000 model year to have been built in 1999, but that doesn't make it a 99.

I have a genuine Jeep XJ Factory Parts List and genuine Jeep XJ Factory Service Manual for both 1999 and for 2000, and nothing in either of the 1999 manuals mentions the coil on plug distributor-less ignition or 0331 head.


My 2000 was built on August 17, 1999 and has the distributor-less ignition and an 0331 head. The VIN and the DMV registration designate it as a 2000.


Report for VIN: 1J4FF58S7YL112xxx


1: Built in United States by DaimlerChrysler Corp.
J: JEEP
4: MULTIPURPOSE PASSENGER VEHICLE
F: 4001 - 5000# (1815 - 2267 kg) GVWR & HYD BRAKES
F: CHEROKEE(4X4)(LEFT HAND DRIVE)
5: CHEROKEE CLASSIC
8: Sport Utility 4 dr.
S: 4.0L 6 CYL Gasoline (MPI) - Unleaded (ERH)
7: Check Digit
Y: 00
L: Toledo Assembly #1 (Toledo, OH)
Body Code: XJJP74
Engine: ERH 4.0L Power Tech I-6 Engine
Transmission: DGS 4-Speed Automatic AW4 Transmission
Build Date: August 17, 1999
 
Last edited:
My 2000 was built on August 17, 1999 and has the distributor-less ignition and an 0331 head. The VIN and the DMV registration designate it as a 2000

Does your exhaust have flanges or is it slip on?
One thing that always confused me was '00's made before 1/20/00.
Been trying to get a handle on how the exhaust is set up on one of those for years.
 
Biggest most sought after upgrade in the '99 vs '98 was a different intake manifold. More rounded for smoother flow for more power. That is what makes the '99 slightly most desirable between '97 - '01 models, before the '00 went to more 02 sensors.

There were a few minor electronic tweaks I believe in the overhead console.
 
Never again 00 or 01, learned my lesson the hard way. Actually im just not going post face lift again. 95-96 is the sweet spot as far as I'm concerned.
 
I've had the heads off all mine & not noticed a difference in inlet manifolds - but then I wasn't looking.

As I only really look at the OHC to put my sunglasses away, "a few minor electronic tweaks" would've passed me by. I mean I do, occasionally, glance at the compass or outside temp just out of curiosity but they really are Christmas cracker style novelties I can live without.

Just revised my thinking on 01's as discovered the Mayor will allow me to keep one outside my London house (& even drive it) without incurring some unsustainable financial penalty after October. The alternative was a 4.7 W but, been there, done that, (probably) never again.
 
Comparison of 98 vs 99 intake manifold...

Inlet_020_small.jpg
 
Yup, they're different alright - but doesn't alter the fact that even when I discovered the '99 head was cracked & immediately set about liberating the one from my parts '96 it didn't register that the inlets were completely different. Of course by the time I came to do the HG on the '97 (a few years later) I'd completely forgotten what the '99 looked like.
 
99 intake is preferred, but not by much
 
Something minor on the '99 and up, is the attachment of the ground strap has a boss and machine threads to attach it with. Both my '98's used a sheet metal screw. I do have a FED 2000. I like it. No real issues.
 
Something minor on the '99 and up, is the attachment of the ground strap has a boss and machine threads to attach it with. Both my '98's used a sheet metal screw. I do have a FED 2000. I like it. No real issues.

If your referring to the one on the intake manifold it's only purpose is shielding.
 
If your referring to the one on the intake manifold it's only purpose is shielding.

No, its on the inner fender on the passenger side. From the alternator, I think. There might be some wiring changes. I was trying to replace the wiring that goes from the front to the rear taillights etc. I had/have one from a 2000 or 2001. One of the plugs is different up by the kick panel on the driver's side.
 
No, its on the inner fender on the passenger side. From the alternator, I think. There might be some wiring changes. I was trying to replace the wiring that goes from the front to the rear taillights etc. I had/have one from a 2000 or 2001. One of the plugs is different up by the kick panel on the driver's side.


Wow, fascinating. That ground always felt super janky for me on my '98. Sheet metal screw for sure. When I redid the battery/ground cables that really stood out as kind of crappy.
 
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