97+ Engine Parts Compatability with 96 & older H.O. 4.0

[Kowboy83]

I have an 87 Comanche with the renix system 4.0 and it blew a head hasket and the rear main seal is leaking. I am wanting to update the whole truck to 97+ interior/exterior and engine. I found a 94 4.0 with 134,000 on it in good shape, the engine in the 97+ parts truck has 180,000 Kinda high mileage for an engine swap. I don't want to spend the time and money rebuilding the 180,000 mile engine.

 

Will 1997 and newer exterior parts work on older engines like exhaust manifolds, intake manifolds power steering pumps etc. ? I did a search but couldn't find any info on it. Any info would be appreciated.

[yellaheep]

It's the engine management systems that will help determine what works and what doesn't......

 

The '94 is OBD I. The '96 and up jeeps were OBD II. Most of the differences where this is concerned are concentrated in the intake manifold and what components/sensors are mounted to it.... Such as MAP sensor location.... '94 was on the firewall, '97+ are on the throttle body.

 

Another issue is power steering bracket mounting to these different intake manifolds over the years. If you retain the '94 intake you'll need the P/S parts from the '94 as the Renix stuff won't work. If you use the '97+ intake you'll need the P/S stuff from that donor as the Renix and '94 stuff won't work.

 

Wiring connector compatibility is a whole other mess. '96 -'97 were big transition years as Jeep worked on conforming to OBD II standards. For instance.... the coil for a '97 won't work on a '96, nor will it work on a '98 all because of different harness connectors. Same fot the transmission control module.... '97 is a one year only application for the TCM. Throttle body sensors have connector differences as well between '96 to '01.

 

Your's really isn't a simple question to answer. Telling us your 180k mile engine is "'97+" still leaves too many possibilities for parts incompatibility as there are differences between '97 - '01.

[cruiser54]

Do this with the 94 and be done with it. Easy.

 

Cruiser’s HO into Renix Swap

 

This swap is easier than some will lead you to believe, generally 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.

 

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

 

Any HO engine from an XJ or ZJ through 1998 can be used. 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 the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head 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 the Renix gasket. Exhaust ports are identical.

You will need to use your Renix distributor as it is different than the HO because they use different fuel management systems. 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.

 

 

Revised 07/24/2012

[mvusse]

96 was a weird year. Sparkles, my daughter's 96 XJ was an early 96 production year. It has OBD II spliced on top of the OBD I harness, Done from the factory, it's a kludge. The parts truck I got was late 96, and it used the same harness as the 97 ones.

 

None of this will affect a 94, though.

[Backdraft]

For what its worth I did the 97+ swap with a 2001 and used everything from the XJ to simplify. The donor engine had 225,000 miles on it when I got it. It currently has 236,000 miles on it in my truck and still runs great, pulls hard, and cruises down the road just fine. My personal opinion is 180,000 miles on a 4.0 isn't terribly high. As long as you have good compression, minimal blowby, and all that jazz, I wouldn't be apprehensive about tossing it in there simply to save the headache of finding out what works with what. Ultimately its your project and your decision, but that's my 2 cents.

[HOrnbrod]

Any HO engine from an XJ or ZJ through 1998 can be used. 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 the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head for the sender.

One note regarding the 96 and up cylinder head and the temp sender bung. The casting number for the 96-99 heads is 0630. According to who/what you read, the 0630 head supposedly flows a little better than the older 7120 (91 to 95 models). Hesco prefers them too on their stroker builds. When I had my stroker built I looked at all the 0630 cast heads Hesco had. The vast majority of them (roughly 2 out of 3) had the correct temp sensor threaded hole with a plug in it. So I ended up using a 98 model head that worked fine. So check the newer heads for the hole first. Nothing is written in stone regarding Jeeps.

[Kowboy83]

Thanks for your input guys. I am leaning toward just swapping out the old renix and putting the higher mileage motor (1997 OBDII) in it after sprucing it up a bit. I don't want to put older technology on newer head as far as puting the renix or OBDI system on the 94 engine. My main question (to clarify) was:

 

Will the 1997-2001 OBDII parts fit an older (96 and older) head/block?

 

My intention is to use one wiring harness (97+) and not having to splice it. I want to keep the 97+ intake manifold and all other external parts and swap them onto the older (read less mileage) 1994 head/block. Will this work?

[FrankTheDog]

Yes, I did the reverse in a ZJ. Put a 97 motor in a 94 with all the 94 sensors and brackets on it.

[Kowboy83]

Thanks frank that's the answer i was looking for. Thanks for the information guys your help is greatly appreciated. Frank were there any problems with fitment or compatibility at all?

[FrankTheDog]

No, 91-98 are pretty much the same as far as mounting points on the block.

Some 99's are compatible if they still have a distributor, not sure if they are if it has coil packs.

Just use what ever year operating system your chassis has and bolt it on the engine.

You can use the later intake with the nicer power steering adjuster too.

Just realize that the belt is routed different.

[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.