2000 XJ engine swap options?

Found another thread from 2011 discussing throwing in a 98 4.0L into a 00 XJ, but it was never resolved I guess, and I'm now in the same boat. Figure a new thread that will see a final resolution is better than reviving a 5yo thread.

Girl didn't check the oil in her civic. I hate working on civics. Bought her a Jeep instead.
Found a suspiciously sweet looking 00 XJ and should've know better, because an XJ that LOOKS good, is always bad. Suspension was obviously pooched but I've got about 3 or 4 XJ's worth of parts and lift stuff at home so I figured it wasn't a big deal. Otherwise looked to be in very good condition. Didn't know about the 0331 head issue *facepalm*.
So yea, head is cracked. On the way home after buying it, got a CEL for low oil pressure. Wasn't making any obvious noise so pulled the pan (gasket needed to be replaced anyway) to check out the oil pump and pickup. Pickup was pretty clogged so cleaned it up. Pump looked okay. Tossed it all back together and OP still drops once warm. Did all the obvious checks, OP may very well just be the sensor but today I noticed the head crack and don't feel like ****ing with this thing anymore.

So that said, I'm sure I can get a pre-00 motor in there just fine, but the easiest way of course would be to just swap the ECU as well and call it a complete 98 motor/harness/ecu swap. Unfortunately, the 00 is an auto and I don't have an ECU for an auto. Looking for suggestions on donors.

I've got a 98 long block left over from my 5.3 swap. It had a few quirks, but always got me where I was going. I'd decided years ago that I'd put the v8 swap off until the 4.0L died, but it of course never did. As I kept building though, the 4.0L was feeling weaker and weaker and I thought it was close enough to dying to justify the swap. Then once I was finished the swap, I finally weighed my rig and it was 5000lbs . So it's entirely possible the old 4.0L was tip top, I was just too fat.
That said, the 98 did have a mysterious loss of coolant (I think) but it always starts instantly, pulls hard, and never let me down. I'm sorta torn about using it.

At any rate, 4.0L long blocks are a dime a dozen. I may just rebuild the 98 I already have, or I may even consider rebuilding the 00 and throwing a TUPY head on it. It's really mostly about downtime as the girl's been getting progressively more pissy about not having a vehicle. I've told her to drive her Jeep into the ground for now and I'll start putting together a swap package.

Option 1.
So, 98 block, head, accessories, and exhaust manifold with the 00 intake and ECU, I've heard should work. Caveats being that I either need to find a way to mount the coilpacks or find room for 3x2 coils somewhere. What gremlins am I going to run into?

Option 2.
Find a 2003+ 4.0L from a wrangler or a slightly later WJ and ... just drop it right in? I've never really worked on Jeeps later than 98 so I'm at a bit of a loss here. I know the wrangler got the TUPY head in 2003 but the grand perhaps later. What all would be involved in this swap? Just grab the long block and drop it all in?

Option 3.
Rebuild the 00 block, drop on a TUPY head, profit???
I've never done a complete rebuild. I'm sure it's not beyond my ability or inclination (I'd actually like to do a rebuild) but machine shop time here is nucking futz. Seriously. For what I've been quoted to pressure test a head, I could just go buy another used longblock. Assuming the 00 block needs work, I'm guessing i'd probably have to turn the crank, new cam, rod/cam bearings, lifters... anything else? Cylinder work required?

Option 4.
???? Any other idea's?


I'm almost seriously considering just tossing in another 5.3 for her. Cost me about $3500 to do mine and only took 3 weeks from the time I started gathering parts. I'm hoping to put less than another grand into the girls XJ as it's just a boring commuter, but I'm almost more comfortable with the 5.3 swap now than I am mixing and matching 4.0L parts .

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These re-designed WJ/TJ engine blocks are not bolt on interchangeable with XJ/ZJ blocks. The motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ. It is possible to drill and tap the necessary holes and to adapt the motor mount brackets. If I recall correctly, somebody, probably BrownDog, makes motor mounts that will do the job.

Any 1990-2001 XJ Cherokee or 1993-98 ZJ Grand Cherokee 4.0 L engine block will interchange. 1997-1999 4.0L TJ Wrangler blocks will also fit in XJ/ZJ. 87-95 YJ engine blocks will probably also fit.

Remove and re-use as needed or required: Intake/Exhaust manifolds, flex plate, cylinder head, distributor-less ignition or distributor assembly, fan belt driven accessories, sensors. If your donor engine has a distributor, the distributor can be removed and a distributor-less ignition assembly can be installed in it place.

If you have a cracked 0331 head, buy a good used redesigned and more durable TUPY 0331 head from a 2002+ 4.0L TJ Wrangler or WJ Grand Cherokee.



Gest option: Good used motor, with a good used TUPY head. Both are easy to find and not very expensive. No changing out stuff, no adapting.

You can use an older non-0331 head on the 2000-01, but you need to buy or fab an adapter plate. I can't find the thread now, but somebody here on used to make and sell the adapter plate.

Tim_MN said:

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These re-designed WJ/TJ engine blocks are not bolt on interchangeable with XJ/ZJ blocks. The motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ. It is possible to drill and tap the necessary holes and to adapt the motor mount brackets. If I recall correctly, somebody, probably BrownDog, makes motor mounts that will do the job.

Any 1990-2001 XJ Cherokee or 1993-98 ZJ Grand Cherokee 4.0 L engine block will interchange. 1997-1999 4.0L TJ Wrangler blocks will also fit in XJ/ZJ. 87-95 YJ engine blocks will probably also fit.

Remove and re-use as needed or required: Intake/Exhaust manifolds, flex plate, cylinder head, distributor-less ignition or distributor assembly, fan belt driven accessories, sensors. If your donor engine has a distributor, the distributor can be removed and a distributor-less ignition assembly can be installed in it place.

If you have a cracked 0331 head, buy a good used redesigned and more durable TUPY 0331 head from a 2002+ 4.0L TJ Wrangler or WJ Grand Cherokee.



Gest option: Good used motor, with a good used TUPY head. Both are easy to find and not very expensive. No changing out stuff, no adapting.

You can use an older non-0331 head on the 2000-01, but you need to buy or fab an adapter plate. I can't find the thread now, but somebody here on used to make and sell the adapter plate.

Click to expand...

Adapter plate for what? From what I've managed to find thus far, the TUPY head should bolt right on to any XJ block. At this point my plan is to either rebuild my 98 block and head, swap over all the 00 sensors and intake, and call it a day. I've no idea though what that'll cost me (machine time) vs just finding a newer 02+ motor with the TUPY head.

Adapter plate for the exhaust manifold. The 0630 and 7120 heads have their exhaust ports in different locations than the 0331, so your 00-01 manifold will not properly line up. Maybe if you have the matching exhaust manifold you can use that also. I have not fully researched the head swap, because my 0331 head is still strong, and because TUPY 0331 heads are getting easier to find in the junkyards.

Read this -> http://www.naxja.org/forum/showthread.php?t=92545

and this -> 0331 to 0630 head swap adapter plate by wilsmick

Good Luck.

Yea, I'd seen this mentioned, but why not just use the older style manifold/header (of which I have several) ?

Good question, unfortunately, I don't have the answer.

Yea, I can't imagine any reason why not unless you have the 00-01 with the two pre-cats (I do not).
Thing is, while 4.0L's are a dime a dozen, there don't seem to be any for sale within a few hundred KM except ones that are clearly beaten to shit and in much worse condition than either of mine. I really suspect I'm going to have to rebuilt one of my blocks, use my 98 head and exhaust and the 00 intake, which isn't a big deal, except that the 98 block and head are also in sorta unknown condition (which is why I haven't sold them, cause I'm not a dick).

Just digging around now trying to figure out what all is involved in rebuilding a short block.

The 98 engine would be a pretty simple swap. Just keep all the accessories and parts from the 2000, except move over the 98 exhaust manifold. You may also need to move the downpipe or rebuild other parts of the exhaust as well. Count your o2 sensors and study the layout.

i swapped a 95 block with a 7120 head into my 2000 years ago. I have had no issues at all. I used everything from my 2000 even the exhaust manifolds with pre-cats. the only thing i did was make little brackets out of aluminum to hold on the coil pack. I have had zero issues for well over 80k miles

Following, please keep this updated if you could. I have a 00 and I am dreading the day I have this problem. I also have a 98 parts rig I have been keeping around just in case this happens.

Will do. Can't say how soon it will be. I'm debating whether or not to just let the girl drive this motor till it blows, or just get the rebuild done over a weekend. I think if I've got the parts all lined up, I should be able to easily get this done in a weekend. Really depends on how it performs over the next few days. I may ultimately end up doing another V8 swap if I happen across a good donor motor for cheap. V8 swap really ain't any more work that rebuilding a 4.0L .

why not just swap a good head onto your motor?

how low is the oil pressure? Every 4.0 I've ever seen has crap oil pressure once hot. If your running anything thinner than 15w-40 I would expect 10-15 psi at idle and not more than 30 if you're lucky at about 2000 rpm, that seems normal. If the current owner used some cheap 5w-30 in there that has thinned out you might only need a new head and oil change

Hoooper said:

why not just swap a good head onto your motor?

how low is the oil pressure? Every 4.0 I've ever seen has crap oil pressure once hot. If your running anything thinner than 15w-40 I would expect 10-15 psi at idle and not more than 30 if you're lucky at about 2000 rpm, that seems normal. If the current owner used some cheap 5w-30 in there that has thinned out you might only need a new head and oil change

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As mentioned earlier, OP is good when cold, drops to 0 when hot. Still getting flow to the head, but got some ticking going on that doesn't sound entirely like lifters. Changed oil twice. 10w30 the first time and 10w30 and a bottle of Lucas the second time. No change. Still have to manually verify the OP with a real gauge, but I'm pretty confident its goona confirm low.

So OP is in fact low. Found lots of stuff wrong with the truck, but most of it is now all good.

Back to the engine though. Girl just called from work and said there was smoke coming from under the hood. I asked her to pop the hood and see where from, but she apparently ... doesn't have time... So told her to just tow it home.

At any rate, new motor time.

00ish XJ 4.0L's are very difficult to find here, and what you do find is destroyed. There's a guy with an 05 TJ 4.0L. Says he busted a couple motor mount bolts off, but looks like there are enough bosses that I could still fab up a mount that'll do the job.

Question is, assuming the 05 motor is complete, is there anything that won't work? Was mated to a manual trans but would need to be mated with an AW4. Will the flex plate bolt right on and are all the sensors pretty much the same?

The 98 block, head, and exhaust will work fine. Swap in the 2k intake, and cam sensor, water temp sender, etc. Make or mod your exhaust crossover pipe. You can make brackets for the coil pack or do the Viper coil pack swap. http://naxja.org/forum/showthread.php?t=1066869 This is basically what I'm running but with a stroker. I wouldn't buy the 05 if your 98 is a known good motor.

What's the TC setup like? I've never had an auto XJ apart. I'm assuming the crank is all the same, and the TC just rides in the flex plate, so I can take a 98 that was mated to a manual, bolt on a flex plate, and it's ready to go yes?

You said you don't have the (2) pre-cats so this may not apply to your 2000 engine swap.

I have done (3) 96-99 motor swaps into 00-01 Cherokee's so far. This is what it generally takes

1) The 0331 has small exhaust ports to force the pre-cats to preheat faster for emissions, therefore the stock exhaust manifold generally will not cover over the earlier motors 0630 and 0720 cylinder bigger exhaust ports. Some just run the gasket to cover the ports, but I always just installed a $135 eBay "2000 Jeep Stainless Header" and used Copper Permatex on both sides of the gasket.
2) Swap Intake and all sensor over to older motor.
3) Install the Cam Sensor where the distributor was, use a toothpick through a hole to set position of sensor before dropping in hole. Suppose to use Jeep Dealer computer to set these but I always done it by ear and been OK
4) Create brackets for the Coil Rail (there is no holes in older heads to bolt them on), I have found the Chevy Starter shims worked great for fastening them to the valve cover studs (I always cut about 1/4" off the bottom of the bolt sleeves where it would touch the head so I can put a bolt upwards to slide on the bracket and put a nut on to secure to the coil rail. PS: I also did the Viper Coil swap on my last swap, I hate them coil rails (Hard to remove in the backwoods - especially that back wire plug, even more so with my Spectre Cowl intake, I have had a number of them go bad, no wires to test for spark in the back woods, expensive, etc)

Its is a fairly easy swap.... except for tightening the two bottom header bolts in the center, they are a PAIN to get to and tighten. HAVE PATIENCE.

blistovmhz said:

What's the TC setup like? I've never had an auto XJ apart. I'm assuming the crank is all the same, and the TC just rides in the flex plate, so I can take a 98 that was mated to a manual, bolt on a flex plate, and it's ready to go yes?

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I haven't done an manual to auto swap, but would guess you would pull the pilot bearing from crank. Test fit the torque converter before installing motor.