• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Diesel XJ - I'm all searched out!

S

Spaz_Soldier

NAXJA Forum User
Location
Winchester, VA
So, I've been searching since the sun was up and it's now past midnight. :wow: Found a lot of good stuff on it. I even had to join some boards I never even knew about. Lol. But, I'm looking at swapping a diesel into my '01 XJ in the future. I know the basics of what I want, but I'm no engine professional. I'm wanting a 4cyl to reduce weight and emissions and help gas mileage. I'd have to get one from a '01 or up vehicle to obey Virginia state laws. It's gotta be able to still maintain highway speeds. I saw the 4bt is popular. I also saw the 3.3L used once or twice. I think the 2.8L CRD is a possibilty. Anybody know what power, fitting, weight, mileage, reliability blah blah blah is like with these different engines? Since this would still, theoretically be my DD, I want to use an automatic tranny (I absolutely SUCK at working a clutch and stick). Any help you guys can give me would be awesome!
 
Last edited:
Spaz_Soldier said:
Also saw the 2.8L CRD was a possibilty. Anybody know what power, fitting, weight, mileage, reliability blah blah blah is like with these different engines?
Click to expand...

The 2.8CRD was around 165bhp and 295lb./ft. as used in the US-spec KJ, which is probably your best source of components for the conversion.

What kind of automatic transmissions could be used?
Click to expand...

With the 2.8CRD, the research I did a few years back indicated that you're pretty much limited to the 545RFE from the KJ. The transmission controller is (IIRC) integrated to the ECU, which you'll need to run the engine anyway. It may be possible to run an AW4 behind it with the proper adapters, but that's a big unknown and the CRD's ECU will almost certainly have fits and throw codes at the very least if you try this. On the plus side, the 545RFE should be reasonably easy to mate to an NP242 in an XJ as that was the standard transfer case for the CRD KJ; I'd expect an NP231 to be a definite possibility.

Supplemental to this, you'll have a fun time with wiring and making gauges and switches work. The CRD's ECU uses a completely different bus to the XJ, so not only will you have to figure out how to make the instruments work with it but any PCM-controlled functions will have to be sorted out as well. This will be non-trivial.

With any diesel conversion it may be necessary to change out the fuel tank, pump, and lines. There are OEM components available for this (as used on the export-model diesel XJs with the VM Motori 2.5TD), but good luck ordering them through Chrysler; their policy is to not provide export-model parts in markets that they weren't intended for. Expect to have to import those from Europe.

FWIW, the 2.8CRD looks like the real sweet spot in terms of diesels that could be dropped into an XJ: fully-optioned it only weighs about 60lbs. more than a fully-optioned 4.0, would package into the engine bay with wiggle room to fit the transmission, and in a vehicle that weighs 800lbs. less than a KJ should provide reasonably decent performance with excellent economy. The downside is that unless you get a rolled CRD KJ cheap at auction, expect just the drivetrain to set you back around $9000 if you order crate components from Mopar.

But if you do it, document the hell out of it. I'm still interested in the idea, but have lost motivation due to considering it impractical as things stand now.
 
Last edited:
Buy a daily driver Honda. Although cool, 4bt swaps are expensive and heavy. I contemplate the swap on a daily basis, but in the end, it always morphs into a huge trail rig. Basically a 4bt 2500 RAM using an xj chassis.
 
casm said:
The 2.8CRD was around 165bhp and 295lb./ft. as used in the US-spec KJ, which is probably your best source of components for the conversion.



With the 2.8CRD, the research I did a few years back indicated that you're pretty much limited to the 545RFE from the KJ. The transmission controller is (IIRC) integrated to the ECU, which you'll need to run the engine anyway. It may be possible to run an AW4 behind it with the proper adapters, but that's a big unknown and the CRD's ECU will almost certainly have fits and throw codes at the very least if you try this. On the plus side, the 545RFE should be reasonably easy to mate to an NP242 in an XJ as that was the standard transfer case for the CRD KJ; I'd expect an NP231 to be a definite possibility.

Supplemental to this, you'll have a fun time with wiring and making gauges and switches work. The CRD's ECU uses a completely different bus to the XJ, so not only will you have to figure out how to make the instruments work with it but any PCM-controlled functions will have to be sorted out as well. This will be non-trivial.

With any diesel conversion it may be necessary to change out the fuel tank, pump, and lines. There are OEM components available for this (as used on the export-model diesel XJs with the VM Motori 2.5TD), but good luck ordering them through Chrysler; their policy is to not provide export-model parts in markets that they weren't intended for. Expect to have to import those from Europe.

FWIW, the 2.8CRD looks like the real sweet spot in terms of diesels that could be dropped into an XJ: fully-optioned it only weighs about 60lbs. more than a fully-optioned 4.0, would package into the engine bay with wiggle room to fit the transmission, and in a vehicle that weighs 800lbs. less than a KJ should provide reasonably decent performance with excellent economy. The downside is that unless you get a rolled CRD KJ cheap at auction, expect just the drivetrain to set you back around $9000 if you order crate components from Mopar.

But if you do it, document the hell out of it. I'm still interested in the idea, but have lost motivation due to considering it impractical as things stand now.
Click to expand...

The horsepower loss with the CRD is negligable, but the torque gain is pretty damn good. I also just found this. Apparently, is pretty popular.
http://www.dieselpowermag.com/tech/0903dp_jeep_cherokee_2_8l_turbo_diesel_conversion/index.html

chpmnsws6 said:
Buy a daily driver Honda. Although cool, 4bt swaps are expensive and heavy. I contemplate the swap on a daily basis, but in the end, it always morphs into a huge trail rig. Basically a 4bt 2500 RAM using an xj chassis.
Click to expand...

Ew! I wouldn't drive a Honda if zombies were chasing me and it was the only vehicle around. Lol. So, a 4bt is possible, but not practical?
 
You've got it! It would make a great trail engine though, with plenty of power to turn even 42's once you play with the pump a bit.
 
Spaz_Soldier said:
The horsepower loss with the CRD is negligable
Click to expand...

No, the loss is anything but negligible. The 4.0 as used in the XJ in 2000 & 2001 was putting out 195bhp; the CRD's 165bhp is 18% less than the 4.0. Make no mistake: that that loss will be noticeable and the torque gain will only go so far to mask it.

I also just found this. Apparently, is pretty popular.
http://www.dieselpowermag.com/tech/0903dp_jeep_cherokee_2_8l_turbo_diesel_conversion/index.html
Click to expand...

Interesting; I hadn't seen that one before. It concerns me somewhat that both the article and the website of the company that did the conversion are low on details, though it is nice to have some slight measure of confirmation on having to use the 545RFE. Leads me to believe that, as suspected, this is not a simple job, particularly when it comes down to the wiring and electrics.
 
Last edited:
The CRD Liberty is actually surprisingly peppy! That swap does look fairly intense in the wiring department.
 
casm said:
No, the loss is anything but negligible. The 4.0 as used in the XJ in 2000 & 2001 was putting out 195bhp; the CRD's 165bhp is 18% less than the 4.0. Make no mistake: that that loss will be noticeable and the torque gain will only go so far to mask it.



Interesting; I hadn't seen that one before. It concerns me somewhat that both the article and the website of the company that did the conversion are low on details, though it is nice to have some slight measure of confirmation on having to use the 545RFE. Leads me to believe that, as suspected, this is not a simple job, particularly when it comes down to the wiring and electrics.
Click to expand...

You think it would still make it to 70mph with 35"s and 4.56 gears? That would be the big winner for me. They can't reveal too much. They gotta be able to make money. Lol.

chasdb said:
How about the TDI?
http://www.hpamotorsports.com/TDI-YJ-AX5.htm
not cheep but kits available, just nut XJ specific
Click to expand...

I've heard they can be somewhat underpowered.
 
Spaz_Soldier said:
You think it would still make it to 70mph with 35"s and 4.56 gears?
Click to expand...

My calculations haven't been based on that tyre size or gear ratio so take this for what it's worth, but given that a 4.0 is capable of moving an AW4-equipped XJ with that combination to that speed, I'd be very surprised if the CRD couldn't. If anything, you would probably have to raise the gearing to keep things sane.
 
VW TDI's with minimal mods can be pretty amazing. Really decent TQ stock, and 200+hp with mild mods. Getting it to work in an XJ, is the hard part.
 
4BT is possible.... there are some floating around in Wranglers. But its probably not the most practical choice.

They are very heavy and you would have to do a lot of modding to fit in a larger radiator to keep it cool.
 
casm said:
My calculations haven't been based on that tyre size or gear ratio so take this for what it's worth, but given that a 4.0 is capable of moving an AW4-equipped XJ with that combination to that speed, I'd be very surprised if the CRD couldn't. If anything, you would probably have to raise the gearing to keep things sane.
Click to expand...

So, it seems this would be my best bet. What about reliability? Is it known to break down easily?

Rmart30 said:
4BT is possible.... there are some floating around in Wranglers. But its probably not the most practical choice.

They are very heavy and you would have to do a lot of modding to fit in a larger radiator to keep it cool.
Click to expand...

True. But, the power it puts out and the sound of it. :loveu: Lol.
 
Rmart30 said:
4BT is possible.... there are some floating around in Wranglers. But its probably not the most practical choice.

They are very heavy and you would have to do a lot of modding to fit in a larger radiator to keep it cool.
Click to expand...

XJ <> TJ/YJ/CJ

4bt is very tall. The couple that I have seen in XJs required 8+" of lift for the pan to clear the front housing.
 
UKJEEP said:
How about simply re-importing a diesel XJ from Europe?
Click to expand...

Regulations here would make it anywhere from difficult to impossible to register. Basically, the 2.5TD XJ was never type-approved for sale in the US, so if you go to <insert vehicle registration body here> and try to register it, the VIN will show it as being an export model and they won't register it for road use. Lighting, instruments, etc. can all be swapped over, but the real issue is that the engine was never emissions-certified for North America.

What you may be able to do is import the engine, transmission, fuel system, etc. from a 2.5TD as parts - customs generally does not like to see whole cars obviously coming in as rolling parts sources - transplant them into a US-model XJ, and (depending on the regulations in your state) register it that way.

That brings up issues of its own, though: because the construction type of the vehicle is generally considered to have been substantially changed when fuel type is changed, that fact needs to be declared at the time of conversion and it may be necessary to submit the vehicle for inspection to verify the fitness and legality of the change. Because the 2.5TD motor was never approved for US sale, its fitment into a US-model XJ may not pass that inspection and you're back to the 'can't get it registered for road use' problem.

The other issue is a practical one: Chrysler will not order parts for a non-US-model vehicle in the US unless the vehicle has been presented at a main dealer with an intact and valid VIN - so your nearest parts source if anything breaks would effectively be scrapyards 3000 miles away (at best).

These reasons are a large part of why the 2.8CRD is one of the better bets out there for an XJ conversion. There's more to this from a regulatory standpoint than just tossing in an engine and calling it done, at least in the US (and it's about 20 times worse if you're in California, but still doable).
 
Last edited:
Just for fun I looked on Car-part.com to see what these engines are going for. For the OP, the nearest one is in NC and is $3100 )plus trans, computer...). They are going for as much as $7500 on the site.

Not looking economically viable.
 
o-gauge-steamer said:
Just for fun I looked on Car-part.com to see what these engines are going for. For the OP, the nearest one is in NC and is $3100 )plus trans, computer...). They are going for as much as $7500 on the site.

Not looking economically viable.
Click to expand...

Is that price for the 2.8CRD?

If so, complete with computer and transmission, that's an absolute steal compared to what they were a couple of years ago.
 
You must log in or register to reply here.

Similar threads

K
XJ paint codes
Replies
5
Views
140
Ken M
K
W
Replacing & Availability - '92 Manual 5-speed
Replies
14
Views
3K
four_shot
four_shot
K
XJ Overland build plan, need a sanity check.
Replies
16
Views
6K
jeep ride
J
B
XJ fuel pump going out?
Replies
5
Views
1K
Anak
Anak
GSequoia
I'm not dead!
Replies
5
Views
507
Bent
Bent
Back
Top