Jeep XJ Cherokee 5.9 Limited?

[JeepinAudiophile]

I may be able to get a running 5.9 engine out of a ZJ and all wiring, etc. to boot... anything off the truck for really great prices. What kind of overhaul am I looking at to put the 5.9 in the XJ... Will it fit? I'm sure someone has researched this before and i'm hoping to tap into their thoughts and tests. Thanx, Chad

 

[Dr. Dyno]

A V8 swap is certainly possible and though the engine bay is tight, it's just about wide enough for a Magnum 5.9 V8. You'll need to relocate the engine mounts and find a way to route the exhaust downpipes (tight space remember?). If you have the computer and wiring, the swap is certainly easier. Your main headache as far as electrics go is getting your gauges to work properly, particularly the tach as it's calibrated for a six banger.
The 5.9 should bolt straight up to the AX15 or AW4 since the bellhousing bolt pattern is the same as that of the 4.0. The problem is that the engine computer is programmed to control a 46RE tranny so the whole swap might be less of a headache if you swap in the ZJ tranny as well. If you have the NP242 TC, it'll be plugn'play. Mating the 46RE to the NP231 shouldn't be a problem either.
Swapping in an engine much bigger than the original entails a cooling system upgrade, so plan on fitting a larger radiator. I don't know if the 5.9 ZJ's radiator will fit in the XJ? If it does, you could also use the 5.9 electric fan.
If you use an automatic tranny, a tranny oil cooler that's separate from the radiator will keep it happy without transferring heat to the coolant.

 

[ArcticXJ]

$$$$$$$$$$$$$$$$$$ ;^)

 

[Dr. Dyno]

$$$$$$$$$$$$$$$$$$ ;^)

Yeah but when you consider that you can get 400+hp/400+lbft out of the 5.9 so easily, it's worth it. Just make sure the rest of the vehicle can take it. You'll definitely need to stiffen up the body and beef up the brakes, suspension, drivetrain, and rear axle. Once you're done, you'll have what will probably be the ultimate sleeper.

 

[JeepSpeed]

Yes, it would be kickass, and it would be the ultimate sleeper, but I don't think it would be worth it. Alot of headaches and hassle. If you can put up with it, more power to you, it would be awesome!! But, I think that an LT1 or even an LS1 would actually end up being cheaper, as well as much more moddable. Maybe even a stroker and a supercharger might end up being easier. XJ Armor is coming out with a blower kit for $2200. Also, the cooling duties would be ridiculous. It's hard enough to keep a 4.0L perfectly cool, cramming a 5.9L would be near impossible. Maybe a bigger radiator, coolant additives, hood vents, and what not just to keep it happy. Good Luck whatever you do!!

 

[scoobyxj]

I have a 98 and the intergration of the computers are outrageous. The tach, speedo,all other gages, tranny [I don't think an AW4 could stand up to a 5.9] even the door locks are computer controlled. They are all linked together by a digital data buss called the CCD buss. here is a section from a 97 FSM,

SPEEDOMETER
​

The micro-processor in the instrument cluster calculates
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the position of the speedometer needle based
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on the vehicle speed signal broadcast on the CCD bus
​

by the Powertrain Control Module. The PCM determines
​

vehicle speed from the input provided by the
​

vehicle speed sensor.
​

TACHOMETER
​

The Powertrain Control Module (PCM) transmits
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the engine RPM data on the CCD bus. From the bus,
​

the instrument cluster calculates tachometer needle
​

position based on the engine RPM signal.
​

I'm not meaning to discourage you but I think it would be impossable to ever get xj guages to work with the 5.9 computer, or even to work corectly without all of the zj's computers.

 

[Gridikal]

bah, ditch the stock gauges all together and hook up some autometers and fab up mounts for them in the stock locations.. who needs a tripmeter anyway :wierd:

 

[JeepinAudiophile]

Hmmm... sounds like much more of a headache than I was expecting... I could easilly keep the motor and tranny together... and I have the 242... The gauges I'd probably go the aftermarket route and make a custom mounts for the pods. I was hoping that someone would tell me that advance adapters makes the motor mounts... but making all the cooling changes, etc. seems like a bit too much work for me. Thanks... if anyone wants the 5.9 parts let me know, i'll try get prices... I'm not sure if the company is taking the thing whole and parting it out later, or If I will definately get free reign on the truck... thanks for the info all!!! --Chad--

 

[scoobyxj]

One thing i didn't think of is the Dakota R/T computer, and harness. That may be a better choice, or try a mopar peformance site for a harness, and computer for there crate engines. A Ram harness flashed with the 5.9's programming [the Ram's program isnt as performance minded as the zj's] might work too.

 

[JeepinAudiophile]

One thing i didn't think of is the Dakota R/T computer, and harness. That may be a better choice, or try a mopar peformance site for a harness, and computer for there crate engines. A Ram harness flashed with the 5.9's programming [the Ram's program isnt as performance minded as the zj's] might work too.

Please elaborate on why I would want to do these? Maybe im just tired, but I could use a little help understanding why I would want to use the factory Dakota brain over the jeep one? The signal starts out the same... Hmmm... stopped to think... I am beginning to understand where you are cmoing from, but I think I would be able to use the signals. If all else fails, I'll just do aftermarket tach, speedo, etc... gives me a chance to fabricate a full-custom dash which would be fun. ERRRRR i'm torn because I want to do this, but I do not have another vehicle to drive this winter, and no real place to do it either. I think it would be too much for me to handle... But If I find out that I will be able to rape the corpse of this ZJ, I think I will steal the engine, tranny, modules, and other workings of the engine in case I choose to do it. At this point it may all be a pipe-dream... I don't even know for sure if I will be able to strip out the guts of the ZJ yet... still waiting on the OK from the yard it's sitting in.

 

[scoobyxj]

J.A. the reason I suggested the truck computers is I doubt they are all digitally linked together like the zj computers are. They probibly use analog signals to talk back and forth.

 

[JeepinAudiophile]

screw it all... i like my 6 banger.... I guess i made up my mind pretty quickly, but i'm gonna strip the ZJ if I can to sell the parts and pay for my stroker... now THAT sounds like a plan! Remember... If anyone wants parts, PM me... i'll get back to anyone who PM's me when I find out if I have access to the ZJ or not. --Chad--

 

[Gridikal]

Please elaborate on why I would want to do these? Maybe im just tired, but I could use a little help understanding why I would want to use the factory Dakota brain over the jeep one? The signal starts out the same... Hmmm... stopped to think... I am beginning to understand where you are cmoing from, but I think I would be able to use the signals. If all else fails, I'll just do aftermarket tach, speedo, etc... gives me a chance to fabricate a full-custom dash which would be fun. ERRRRR i'm torn because I want to do this, but I do not have another vehicle to drive this winter, and no real place to do it either. I think it would be too much for me to handle... But If I find out that I will be able to rape the corpse of this ZJ, I think I will steal the engine, tranny, modules, and other workings of the engine in case I choose to do it. At this point it may all be a pipe-dream... I don't even know for sure if I will be able to strip out the guts of the ZJ yet... still waiting on the OK from the yard it's sitting in.

ha, who needs gauges to drive lol. Rip it out, do a full custom dash with aftermarket gauges... that'll just give me the motivation to follow suit

 

[surfnturf]

That would be a lot of work. I got the Avenger supercharger in mine and it puts out tons of power. The full job, installed and all, will run you about 5k, with no loss in gas mileage or driveability.

 

[JeepinAudiophile]

I know, it was just a thought that i needed to be talked out of. I looked at the avenger setup(my favorite) but i think i'd like to go the stroked road first... it'll cost me about the same, and I can always slap some forced induction on there later... I was actually going to contact avenger to see if I change the pulley on the charger if it can safely pute out enough cfms to bring it back up the propper boost with the additional combustion space i'd get with a 4.6L- but at that point, I am way out of my current price range... hell, even the stroker is out of it- but i have a plan!!!

 

[AndyS]

Don't plan on ever passing emissions here in MA again if you swap the 5.9 into your XJ....

 

[JeepinAudiophile]

hmm.. good thought... i guess that's one more straw on the camels back.

 

[Dr. Dyno]

i think i'd like to go the stroked road first...

You'll love the stroker and it's not as expensive as you might think if you cherry pick parts.

 

[JeepinAudiophile]

You'll love the stroker and it's not as expensive as you might think if you cherry pick parts.

I know, I know.... But honestly, I don't think I should tackle building my stroker as my first engine job... just doesn't seem like a good idea, I don't have the time, or place to work on it now anyways... nevermind that i'm going to have to wait atleast a few months before can sell enough of the ZJ parts to pay for the stroker. I'll end up paying Mike Accurate Power for their stroker... but atleast I will have the peace of mind knowing that everything was done correctly by a company who has built hundreds if not thousands of engines.

 

[JeepinAudiophile]

That would be a lot of work. I got the Avenger supercharger in mine and it puts out tons of power. The full job, installed and all, will run you about 5k, with no loss in gas mileage or driveability.

Plus... you get to put a huge, kick-ass scoop on the hood of your jeep... when people point at it or say anything, all you have to do is put your foot into the skinny pedal a bit and show them what's up...