Im by no means mechanically inclined so I apologize in advance if this is a dumb question. Recently I was been rear ended and insurance totaled my 1997 Grand Cherokee and I've wanted a Cherokee instead. I figured that if I got a Cherokee with a blown motor and bought the ZJ back, a 4.0 I6 of course, I could just swap the engines over. Im not sure if this is actually feasible or not so if you have any advice or suggestions let me know. Thanks in advance fellas!

 

Very easy to do. CRUISER'S MOSTLY RENIX TIPS

HO INTO RENIX SWAP

OCTOBER 31, 2015 SALAD 48 COMMENTS

This swap is easier than some will lead you to believe. And generally Pooh-poohed by those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

• XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.
• 2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.
• YJ and 1997-1999 4.0L TJ blocks will interchange in XJ/ZJ
• XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications.

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.

Now that we know which engines we can use, let’s get down to business.

The HO and Renix have some differences but none that can’t be overcome very easily.

One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from an HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head at the rear for the sender.

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use a new Renix gasket. Exhaust ports are identical.

An alternative on exhaust manifolds:

As far as exhaust, you can use the Renix exhaust manifold and be fine.
If you want to use the HO exhaust manifold, you must go with an HO headpipe and screw your O2 sensor into that headpipe. Standard Renix harness is plenty long to do so.
A bung can be welded into the HO manifold to accept the EGR tube.

You will need to use your Renix distributor as it is different than the HO design. See Tips #12 – Setting Your 4.0 to #1 TDC and #13 – Distributor Indexing to be sure you get the distributor installed correctly.

The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.



XJ: “Regular” (not Grand) Cherokees ’84-’01
ZJ: Grand Cherokee ’93-’98 (Gen1)
WJ: Grand Cherokee ’99-’04 (Gen2)
YJ: Wrangler ’87-’95 (Gen1)
TJ: Wrangler ’97-’06 (Gen2)

 

Have you got a potential vehicle lined up? Just wondering because it seems like it would be more cost effective to find a decent XJ with a functional engine and just buy it rather than (probably overpaying to) buy back the ZJ. Is there a particular reason why the ZJ engine + swap would be more desirable than a running XJ?

 

But, if you have the room to store and part out the ZJ, that's a different story.

 

I'm certainly not pooh-poohing the idea, just curious as the logical thing seems to me to just put the insurance check and whatever extra "new vehicle" money into buying the best used XJ you can find - especially if you're not already set up with a full garage of specialty tools.
However, if the O.P. had - for example - just put a $4000 stroker engine in it 1k miles ago - well, then I'd want that engine out of it no matter what hoops the insurance company wanted to put me through.

 

" insurance totaled my 1997 Grand Cherokee " What is the "price" (for the ZJ?). Also finding a decent pre 00 with a blown 4.0 might not be so easy! Here is all of Craigslist> http://www.searchcraigslist.org/

 

Yeah I've got an 01 lined up for 900, rust free as its never been north of Tennessee, no dents and an immaculate interior. The CO doesn't have the money to invest in fixing it and it has a blown head gasket. Might need a new radiator as well but that fixable. My father and I just recently put a bunch of time and money fixing the ZJ engine and I thought it might be cheaper to do it this way as the price for a clean Cherokee with a blown motor seems to be 4x less than a ****box with a running one. As stated before though I known very little about this kind of stuff so any advise is apprecciated

 

Ahhh that makes sense.

So as Cruiser noted the ZJ engine will swap into the 01 as far as motor mounts, accessory locations, transmission mating etc - the only difference is in the intake/exhaust mating - but there's info about making it work... basically minor differences in the sizes of the ports.. it will bolt up, so no major modifications AFAIK.

The 01 probably suffered the well known and common casting defect, so it's likely a cracked head (so a little worse than just a failed gasket). If you're not familiar with it, look up 0331 head defect and you'll find a ton of info.

Swapping the engine over is not a technically difficult job, just a lot of work and you'll need to buy or make some specialized equipment to pull the 500lbs of engine in and out of the Jeeps.

900 for a clean, well kept 01 with only a bad engine sounds like a good deal and excellent project if you don't mind getting your hands dirty. Your 97 engine will definitely work. The only 2 things to read up on are the 0331 manifolds as I mentioned and dealing with the fact that you'll be going from a distributor system on the 97 to a coil rail system on the 01.

I'd go for it if it were me.

 

Radiators are cheap and fairly easy on the XJ as well.

 

Thanks for the info man I think Im gonna pull the trigger on this XJ in that case! I'm sure I'll have more questions along the way but one step at a time

 

Well, good luck on the project! This forum is a life-saver and there are ton of awesome and super knowledgeable folks that are regular members. Some other awesome resources are xjjeeps.com (technical manuals), Bleepin' Jeep (youtube videos) and of course, Cruiser's website (cruiser54.com) - it's geared toward Renix era XJ/MJ Jeeps (87-90), but plenty of stuff that applies to the later models and the technical manuals section definitely has PDF's of the FSM for 00 (which is very close to the 01) and may have the 01 manual.

I also strongly encourage you get a copy of the parts manual for your year - aside from having the part numbers for stuff, the many diagrams are great for visualizing how stuff goes together.

Keep us posted on the project!