95compact

Any problems or, brackets or adapters needed to put a 2000 XJ's I-6 into a 1988 Commanche (to replace its own tired out I-6)?

Thanks!

00jeepXJ

you will need to make sure that all your sensors have the proper mounting points. Also the 2000 4.oL engine uses a coil pack in a strip. This may made it so that you don't have the proper mounting points for some of your ignition system.

NorCalJeep

If i remember correctly you have to use some old things off the old 88 motor, but i can't remember them right now (fail).

DFlintstone

Well darn. I just failed to fine a recent thread that would have been nice. It might be "prickly", since the 2000, 2001 heads won't take the earlier manifolds. You are gonna stay with your 88 ECU, and I don't think it's gonna like the 2000 manifold and the coil packs. Worse, the your 88 manifolds won't go without an adapter plate. I think you CAN put a 91 to 99, HO head, (or use your Renix head, 2686), then your manifolds on that head. Then put your distributor, and flywheel/flexplate in it as well.

Well there's enough to start a discussion. If somebody can find post #52 in that other thread that might be nifty.

http://www.jeep4.0performance.4mg.com/tech_specs.html

cruiser54

XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.

2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.

XJ/ZJ blocks and 2000+ TJ/WJ blocks do not interchange without significant modifications. (1997-1999 4.0L TJ Wrangler blocks will interchange in XJ/ZJ and visa-versa).

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is 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.

95compact

Great info guys!

So I'll need to make sure then that the new block is actually out of a 2000, rather than 1999-. I bought it years ago with the intent to put it in my '92 XJ - just never got around to it and now a friend wants it for their '88 MJ. I know that it has the 'position sensor' in place of the mechanical distributor and it has/had the coil pack on it as well.

The plan is to use only the 'block' (I mean from valve cover to oil pan and everything in between) - so the manifolds and accessory mounting points will have to match.

Will the engine serial number allow us to figure out exactly what block it is?

I can get that info today.

Thanks again!

salad

Block casting number will tell you which block it is hehe, if you know for sure that it has coil packs though that's what actually matters. That is the 0331 head and makes it a 2000+ model year with fancy distributorless ignition and complex emissions. If you're set on keeping the whole engine (the block is just between the oil pan and head) then you'll need the donor's ECU. I'm not sure how to address the cable vs electric speedometer or other gauge cluster differences. Seems more straightforward to find a Renix head

95compact

Haha, yeah I thought about that shortly after I posted!

I thought I had done the research years ago when I bought the engine, but I guess I missed this big one!

Will the '88 Commanche's cylinder head fit the 2000 block properly? I'm ASSuming that the Commanche's head is part of the reason for replacing the engine, but if they were to have it overhauled could we just swap the 2000 block in and remount everything else (head, manifolds, ecu, accessories, etc)?

XJ?2010

The only sensor that will be wrong will the the coolant temp sensor. I put a 99XJ motor in my 87 Manche. Worked fine just transfer over all your brackets and mounts. You could swap the 88 head onto the 2000 bottom end if you wanted. If you do use the 2000 head your intake and exhaust manifolds will be a little bit off.

5-90

Bear in mind that the 4.2L (6-258) engine ceased production at the end of the 1990MY...

The mounting should be the same (I believe it's the YJ and TJ that are different.

If you just need the short block, you're going to have an easier time swapping that than you will making the whole engine work. The intake ports were raised for 1991, so the earlier manifold will require work to adapt. Also, the TPS differs, you'll have to adapt the RENIX TPS to the HO throttle body, if you go that route (it can be done, I don't recall how offhand. But, there are threads over on NAXJA that will tell you what you need to do - with pictures!)

The 2000 block will not have the boss drilled/tapped to accept the knock sensor. However, this isn't a big problem. Two possible solutions:
- The boss is still there. Drill and tape M10-1.5 to accept the knock sensor. You do not need to go through, you probably only need 15-20m/m of thread depth (check your sensor, add a few m/m to the thread length. If you do go through, be sure to use thread sealer - but you don't need to go through.
- Leave it alone. The knock sensor, if everything is working properly, is only "along for the ride." The knock sensor will only generate a signal if it detects spark knock - else, it's just there.

But, it's usually less work to adapt the short block backwards to RENIX and drop the head on, than to adapt the top end to make it work. It can' be done, but how much work do you want to do?