4.0 Cylinder Block Interchangeability

Chris

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@UPJOHN recently ran into an issue thinking that a 2001 Cherokee XJ 4.0 would be a direct swap into his son's TJ. He ran into a number of issues as outlined in this thread: XJ 4.0 into TJ: Hardest engine swap ever. Because of that thread, I wanted to make a FAQ resource out of this topic, since it may help others in the future.


So which 4.0 blocks will interchange, and which ones won't?
Here is some information on 4.0 cylinder block interchangeability:
  • XJ and ZJ Grand Cherokee 4.0 engine blocks interchange.
  • 2000+ Wrangler TJ and WJ Grand Cherokee 4.0 blocks interchange.
  • XJ / ZJ 4.0 blocks and 2000+ TJ / WJ blocks DO NOT interchange without significant modifications.
  • 1991 to 1995 Wrangler YJ and 1997-1999 Wrangler TJ 4.0 blocks will interchange in XJ / ZJ and vice versa.
TJ / WJ 4.0 engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand Cherokee and 2000 TJ Wrangler. These blocks are not interchangeable with XJ / ZJ engine blocks. The reason is due to the motor mount bolt holes and belt driven accessory mounting bolt holes being in different locations, or not present at all (TJ / WJ vs. XJ / ZJ).


Model Guide:
  • XJ: Jeep Cherokee (84-01)
  • ZJ: Jeep Grand Cherokee (93-98)
  • WJ: Jeep Grand Cherokee (99-04)
  • YJ: Jeep Wrangler (87-95)
  • TJ: Jeep Wrangler (97-06)

If I've left anything out, please let me know. As far as cylinder heads go, there are some differences I believe, but I'm not 100% sure on what they are.
 
Jeep 4.0 Engine (1996-1998)

Fits the following vehicles:

1996-1998 Jeep Cherokee 4.0 Auto or Manual
1996-1998 Jeep Grand Cherokee 4.0 Auto or Manual
1997-1998 Jeep TJ Wrangler 4.0 Auto or Manual

This is due to holes for mounting accessories. A/C location is a big one.
 
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@UPJOHN recently ran into an issue thinking that a 2001 Cherokee XJ 4.0 would be a direct swap into his son's TJ. He ran into a number of issues as outlined in this thread: XJ 4.0 into TJ: Hardest engine swap ever. Because of that thread, I wanted to make a FAQ resource out of this topic, since it may help others in the future.


So which 4.0 blocks will interchange, and which ones won't?
Here is some information on 4.0 cylinder block interchangeability:
  • XJ and ZJ Grand Cherokee 4.0 engine blocks interchange.
  • 2000+ Wrangler TJ and WJ Grand Cherokee 4.0 blocks interchange.
  • XJ / ZJ 4.0 blocks and 2000+ TJ / WJ blocks DO NOT interchange without significant modifications.
  • 1991 to 1995 Wrangler YJ and 1997-2999 Wrangler TJ 4.0 blocks will interchange in XJ / ZJ and vice versa.
TJ / WJ 4.0 engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand Cherokee and 2000 TJ Wrangler. These blocks are not interchangeable with XJ / ZJ engine blocks. The reason is due to the motor mount bolt holes and belt driven accessory mounting bolt holes being in different locations, or not present at all (TJ / WJ vs. XJ / ZJ).


Model Guide:
  • XJ: Jeep Cherokee (84-01)
  • ZJ: Jeep Grand Cherokee (93-98)
  • WJ: Jeep Grand Cherokee (99-04)
  • YJ: Jeep Wrangler (87-95)
  • TJ: Jeep Wrangler (97-06)

If I've left anything out, please let me know. As far as cylinder heads go, there are some differences I believe, but I'm not 100% sure on what they are.
The main cylinder head difference is the lack of mounting bosses that are drilled and tapped to mount the coil pack. While that could be overcome with a few tabs off of the valve cover bolts, there are other bosses missing as well.

The big one between the 99 and 00 block is the way the hole in the block is shaped for the water pump.
 
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Reactions: Chris
@UPJOHN recently ran into an issue thinking that a 2001 Cherokee XJ 4.0 would be a direct swap into his son's TJ. He ran into a number of issues as outlined in this thread: XJ 4.0 into TJ: Hardest engine swap ever. Because of that thread, I wanted to make a FAQ resource out of this topic, since it may help others in the future.


So which 4.0 blocks will interchange, and which ones won't?
Here is some information on 4.0 cylinder block interchangeability:
  • XJ and ZJ Grand Cherokee 4.0 engine blocks interchange.
  • 2000+ Wrangler TJ and WJ Grand Cherokee 4.0 blocks interchange.
  • XJ / ZJ 4.0 blocks and 2000+ TJ / WJ blocks DO NOT interchange without significant modifications.
  • 1991 to 1995 Wrangler YJ and 1997-1999 Wrangler TJ 4.0 blocks will interchange in XJ / ZJ and vice versa.
TJ / WJ 4.0 engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand Cherokee and 2000 TJ Wrangler. These blocks are not interchangeable with XJ / ZJ engine blocks. The reason is due to the motor mount bolt holes and belt driven accessory mounting bolt holes being in different locations, or not present at all (TJ / WJ vs. XJ / ZJ).


Model Guide:
  • XJ: Jeep Cherokee (84-01)
  • ZJ: Jeep Grand Cherokee (93-98)
  • WJ: Jeep Grand Cherokee (99-04)
  • YJ: Jeep Wrangler (87-95)
  • TJ: Jeep Wrangler (97-06)

If I've left anything out, please let me know. As far as cylinder heads go, there are some differences I believe, but I'm not 100% sure on what they are.
Can you tell me I have a 98 zj 4.0 runs drives fine just want to swap everything into my 98 tj wrangler with 2.5 is this possible thanks in advance
 
Can you tell me I have a 98 zj 4.0 runs drives fine just want to swap everything into my 98 tj wrangler with 2.5 is this possible thanks in advance

It's possible, but it's going to be a headache as oppose to getting a 4.0 out of another TJ.
 
Tell me if I'm understanding correctly. I have an 03 tj, my buddy has a 98 tj. We both need lower ends. Another buddy has an 01 cherokee motor he'll give me. None of the blockswill interchange?
 
Tell me if I'm understanding correctly. I have an 03 tj, my buddy has a 98 tj. We both need lower ends. Another buddy has an 01 cherokee motor he'll give me. None of the blockswill interchange?

Correct, not without significant modifications which ultimately isn't worth it in my opinion. You'll just be causing a headache for yourself.
 
Jeep 4.0 Engine (1996-1998)

Fits the following vehicles:


1996-1998 Jeep Cherokee 4.0 Auto or Manual
1996-1998 Jeep Grand Cherokee 4.0 Auto or Manual
1997-1998 Jeep TJ Wrangler 4.0 Auto or Manual

This is due to holes for mounting accessories. A/C location is a big one.
Would a 96-98 Jeep cherokee 4.0l engine block can be swap in a 01 Jeep Wrangler sport 4.0l body
 
@UPJOHN recently ran into an issue thinking that a 2001 Cherokee XJ 4.0 would be a direct swap into his son's TJ. He ran into a number of issues as outlined in this thread: XJ 4.0 into TJ: Hardest engine swap ever. Because of that thread, I wanted to make a FAQ resource out of this topic, since it may help others in the future.


So which 4.0 blocks will interchange, and which ones won't?
Here is some information on 4.0 cylinder block interchangeability:
  • XJ and ZJ Grand Cherokee 4.0 engine blocks interchange.
  • 2000+ Wrangler TJ and WJ Grand Cherokee 4.0 blocks interchange.
  • XJ / ZJ 4.0 blocks and 2000+ TJ / WJ blocks DO NOT interchange without significant modifications.
  • 1991 to 1995 Wrangler YJ and 1997-1999 Wrangler TJ 4.0 blocks will interchange in XJ / ZJ and vice versa.
TJ / WJ 4.0 engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand Cherokee and 2000 TJ Wrangler. These blocks are not interchangeable with XJ / ZJ engine blocks. The reason is due to the motor mount bolt holes and belt driven accessory mounting bolt holes being in different locations, or not present at all (TJ / WJ vs. XJ / ZJ).


Model Guide:
  • XJ: Jeep Cherokee (84-01)
  • ZJ: Jeep Grand Cherokee (93-98)
  • WJ: Jeep Grand Cherokee (99-04)
  • YJ: Jeep Wrangler (87-95)
  • TJ: Jeep Wrangler (97-06)

If I've left anything out, please let me know. As far as cylinder heads go, there are some differences I believe, but I'm not 100% sure on what they are.

So.....if I'm reading this right! Lol a straight 6 xj 91.. will fit my tj 97 2.5L with not much trouble?!? Thanks for any help you can throw my way😁
 
Hi all, may be this a good place to ask. Oil Pan interchangeability? baffles no or not etc... Can the ZJ pan be used on 2000+ TJ

My question is more about Rear Main Seal... does anyone know of pan dimension changes etc affecting sealing on skirt of block? I've don the Rear Main 2x... it leaks worse than original leak. I also did the used a pan from a ZJ with baffle, this is a 2004 TJ. As much as I've searched and read, there is no issue mentioned or warnings from others. Everyone talks about the baffle and exhaust clearances.

Thoughts please as it relates to Oil Pan and Rear Main. As I go for 3rd time on Rear Main.
 
Will a 98 4.0 out of a TJ go into a 99 TJ? I've read through all the forum posts and I *think* it will but I note that the engine management computer on the '99 was updated to a "JTEC+" and wondering if that will have any issues on the 98?

<edit to add: the 98 is free and I'm looking to do a full rebuild on it first before installing>
 
Will a 98 4.0 out of a TJ go into a 99 TJ? I've read through all the forum posts and I *think* it will but I note that the engine management computer on the '99 was updated to a "JTEC+" and wondering if that will have any issues on the 98?

<edit to add: the 98 is free and I'm looking to do a full rebuild on it first before installing>

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