Looking for info on putting an XJ 4.0 into a 2.5 TJ

Larrathos

New Member
Joined
Mar 16, 2016
Location
Chandler AZ
Okay so I drove my 1999 Jeep Cherokee Sport into an embankment and my insurance company totaled it. I can buy the Jeep back for less than $400 and the Engine, Transmission, transfer case and drive shafts are all fine. I was wondering about buying it back and then buying a 4 cyl TJ and putting my 6 cyl into the TJ since the 4 cyl TJs are so much cheaper. Has anyone does this and is there a year or range of years of TJs that would accept the 99 XJ engine the easiest? What are the hardest parts and what else would I need to buy? What on the TJ would I have to modify?


I’ve been reading around and the big problem I see people run into is the wiring harness and the PCM but I have both of those in the XJ.
 
@shawn i think put together a pretty extensive list of swap parts when he did his.
He bought a wrecked TJ and swapped it into a TJ and when he was done said "if I had it to do over Id have sold them both and bought a 4.0 tj"...I think thats what he said between profane words
 
I don't know enough about the XJ to say for sure. The front dress is different, so you'd still need that (and the fan/fan shroud/etc) from a TJ. I would bet against the wiring harnesses being the same. The only way you might get lucky is if the donor TJ is also a 99.

You'd definitely have to build motor mounts from scratch.
 
I do alot of engine swaps. since u stated u was going to buy a 4cyl tj. my suggestion is buy a 6cyl tj. to me the work involved to do this conversion isnt worth it. its no less trouble than doing a v8 swap. but then you have the added hp and performance of a v8. most of us that do this swap will tell u. u get better mpg out of an ls swap tj than 4.0
 
Why mess around with anything less than a HEMI!?

OK..kidding aside, I was SO close to pulling the trigger on a proper built TJ. I mean it had EVERYTHING I ever wanted, but was a 4cyl

In the end, after MUCH research I bought a 4.0 equiped stock TJ and built it myself...ended up being cheaper and less headaches than the 4.0 swap
 
You will not be able to use the factory 4.0 TJ motor mounts, the XJ block has different bosses cast in for the mounts.
 
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