Cheap 01 XJ engine into 06 LJ

[daylee6003]

hey everyone, i have decided to look for a new engine instead of getting the piston rings fixed on my LJ. i have been quoted 1.2k with potential to cost more depending on what was found. I found a 01 XJ engine for $750 delivered to me with 118k miles. I have seen some posts on here with people saying that XJ engines can be a pain in the older TJ's. Would i be better off trying to find a different engine?

thank you for the help.

 

[daylee6003]

I also saw on a post a guy mentioned he swapped a engine over and finally got it running great but wasnt able to get the AC connected.

 

[Chris]

You'll be far better off trying to find an engine that came out of the same year of TJ. That XJ engine is going to give you several headaches.

 

[TJ4Jim]

hey everyone, i have decided to look for a new engine instead of getting the piston rings fixed on my LJ. i have been quoted 1.2k with potential to cost more depending on what was found. I found a 01 XJ engine for $750 delivered to me with 118k miles. I have seen some posts on here with people saying that XJ engines can be a pain in the older TJ's. Would i be better off trying to find a different engine?

thank you for the help.

This is what google AI is saying:

Key Differences & Challenges:

• Block Design: Your 2006 TJ (2000-2006 TJ) uses a newer 4.0L block casting, while the 2001 XJ is from the older series.
• Motor Mounts: The bolt holes for motor mounts are in different locations, so you'll need custom mounts or modify the existing ones.
• Ignition: The 2001 XJ engine likely has a distributor, while the '06 Wrangler uses a coil rail ignition system; you'll need to adapt the coil rail to the older engine or use the older ignition system.
• Emissions: The 2001 XJ has a more complex precat exhaust with multiple O2 sensors; adapting this to the older engine can be tricky, notes Reddit users.
• Temperature Sender: Later engines moved the temp sender hole; you might need to tap the thermostat housing on the XJ engine for the TJ's gauge, say

 

[daylee6003]

You'll be far better off trying to find an engine that came out of the same year of TJ. That XJ engine is going to give you several headaches.

okay thank you, should i stay away from early TJ engines as well?

 

[daylee6003]

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This is what google AI is saying:

Key Differences & Challenges:

• Block Design: Your 2006 TJ (2000-2006 TJ) uses a newer 4.0L block casting, while the 2001 XJ is from the older series.
• Motor Mounts: The bolt holes for motor mounts are in different locations, so you'll need custom mounts or modify the existing ones.
• Ignition: The 2001 XJ engine likely has a distributor, while the '06 Wrangler uses a coil rail ignition system; you'll need to adapt the coil rail to the older engine or use the older ignition system.
• Emissions: The 2001 XJ has a more complex precat exhaust with multiple O2 sensors; adapting this to the older engine can be tricky, notes Reddit users.
• Temperature Sender: Later engines moved the temp sender hole; you might need to tap the thermostat housing on the XJ engine for the TJ's gauge, say

thank you for that! im going to keep looking and hope that i can find a TJ engine for my jeep instead. Any clue what a good price range is for a TJ engine? i found one for $1200 with 100k miles

 

[TJ Jim]

What’s the reason for not doing a rebuild on yours?

 

[Chris]

@mrblaine will know all the differences better than anyone on here. If we're fortunate enough he'll leave some of his knowledge here.

As I understand it you want to try and find one from a TJ that is within a year or two of yours for the fewest changes possible.

 

[akajibio]

I think for all the headaches that come with cross matching engines, I'd rather take the engine to a good reputable builder and have them rebuild your own motor. Just my two cents.

 

[daylee6003]

What’s the reason for not doing a rebuild on yours?

I could go that route as well. what should i have rebuilt on mine? im not very handy or familiar with engines. I would hate to get the piston rings fixed and then something else on my engine go wrong soon after. it has almost 200k miles

 

[lBasket]

Thread '4.0 Cylinder Block Interchangeability'

Thread '4.0 Cylinder Block Interchangeability'

Dec 27, 2018

@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...

• Chris
• Replies: 28
• Forum: TJ Resources

• 

 

[mrblaine]

hey everyone, i have decided to look for a new engine instead of getting the piston rings fixed on my LJ. i have been quoted 1.2k with potential to cost more depending on what was found. I found a 01 XJ engine for $750 delivered to me with 118k miles. I have seen some posts on here with people saying that XJ engines can be a pain in the older TJ's. Would i be better off trying to find a different engine?

thank you for the help.

Doesn't matter. The 4 liter isn't worth 750 with next to zero miles on it. One with over a 100 thousand is not worth the effort to swap it in if it was free.

 

[Chris]

I could go that route as well. what should i have rebuilt on mine? im not very handy or familiar with engines. I would hate to get the piston rings fixed and then something else on my engine go wrong soon after. it has almost 200k miles

Rebuilding yours would be the smart route to go.

 

[TJ Jim]

I could go that route as well. what should i have rebuilt on mine? im not very handy or familiar with engines. I would hate to get the piston rings fixed and then something else on my engine go wrong soon after. it has almost 200k miles

At the minimum rings and bearings. Best to replace the oil pump, and timing chain. If I did it I’d send the head and have a shop rebuild that part. I’ve heard that the new parts these days aren’t too good. New cam bearings would also be a good idea, which letting a shop replace those would be a good idea since the installation tools are expensive for a one time user. I’ll be doing mine when the time comes because rumor has it rebuilt motors aren’t great.

But I’m still curious why you want to replace it? Mine has 208,000 miles on it now, and I’d drive it coast to coast and not worry about it. Rumor has it they make 300-400k if serviced regularly.

 

[daylee6003]

At the minimum rings and bearings. Best to replace the oil pump, and timing chain. If I did it I’d send the head and have a shop rebuild that part. I’ve heard that the new parts these days aren’t too good. New cam bearings would also be a good idea, which letting a shop replace those would be a good idea since the installation tools are expensive for a one time user. I’ll be doing mine when the time comes because rumor has it rebuilt motors aren’t great.

But I’m still curious why you want to replace it? Mine has 208,000 miles on it now, and I’d drive it coast to coast and not worry about it. Rumor has it they make 300-400k if serviced regularly.

thank you. Maybe i will look into just having it rebuilt instead. I will talk to my mechanic about it. Im hoping i can get it rebuilt and get another 200k miles out of the engine haha. Thank you for the help. I bought my LJR because it had minimal rust. I put maybe 2k miles on it before the engine started to run rough and misfire. took it to a shop and they said clyinder 3 had low compression.

 

[TheBoogieman]

took it to a shop and they said clyinder 3 had low compression.

Just like with doctors. it's always best to get a second opinion.

 

[daylee6003]

Just like with doctors. it's always best to get a second opinion.

For sure. The first shop wanted to charge me almost 4000k and said cylinder 3 had 0 psi. 2nd shop said it had some compression but it was low.

 

[mrblaine]

At the minimum rings and bearings. Best to replace the oil pump, and timing chain. If I did it I’d send the head and have a shop rebuild that part. I’ve heard that the new parts these days aren’t too good. New cam bearings would also be a good idea, which letting a shop replace those would be a good idea since the installation tools are expensive for a one time user. I’ll be doing mine when the time comes because rumor has it rebuilt motors aren’t great.

But I’m still curious why you want to replace it? Mine has 208,000 miles on it now, and I’d drive it coast to coast and not worry about it. Rumor has it they make 300-400k if serviced regularly.

I've dealt with far more sub 150,000 mile motors in need of replacement, rebuild, or some catastrophic repair that made them need to get swapped out to ever give any credibility to that rumor.

 

[mrblaine]

For sure. The first shop wanted to charge me almost 4000k and said cylinder 3 had 0 psi. 2nd shop said it had some compression but it was low.

4 million is a lot for a motor swap. I'd find another shop.

 

[daylee6003]

4 million is a lot for a motor swap. I'd find another shop.

that is a funny typo. i meant 4k. haha!