Expat_PM

My son's 88 Cherokee needs an engine. What years will fit it?
Is it true that I an use any 4.0 from 86 through 91? Heard that from a friend who may or may not be reliable.

Having a devil of a time finding one.

1994

4.0 inline 6's were used in cherokees from 87-2001 and weren't completely discontinued until 2006.

BUT ... in 91' Chrysler started making mods to it resulting in a 190HP engine badged "HIGH OUTPUT" -- with a new fuel injection system replacing the RENIX system, the intake ports were raised and the throttle body enlarged somewhat. Chrysler also redesigned the intake and exhaust manifolds and the fuel injectors were replaced with higher flow units. Camshaft timing also changed.

SO you will definitely need an 87-90 build 242 ... here's one for $275 plus $200 shipping ... but it has 271k miles on it. Owner says it "runs nice" ... and these engines ARE known to be long lifers. http://www.ebay.com/itm/87-88-89-90-...f25b12&vxp=mtr

Good luck ...

bubbarules1958

See post 17. You can put a HO in it. This man knows his stuff. https://www.cherokeeforum.com/f51/cr...x-tips-153657/

Firestorm500

From what I understand, the only direct swap is another 4.0 from 87-90. You can also use a later 4.0 if you treat it as a long block swap, using all the Renix outer accessories and gaskets.

Stay away from 00-01s as they have a casting flaw in the head. They often crack. You would also have to fab up a coil rail mount.

An engine rebuilder told me when it became time to rebuild my '87 4.0, they would have to use my engine as there are no good cores available anymore.

I think a lot of them got eliminated in the cash-for-clunkers campaign.

cruiser54

Absolutely incorrect!!

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 1999 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 03/28/13

cruiser54

Where are you located?

Expat_PM

Thanks everyone!
Great feedback.

Cruiser, I'm in Alabama.
A friend owns a busy wrecker service and has seen a couple come through his yard but they were all later than 91 and we thought they would not work.
I'll let him know that the next one he finds (87 through 99) that I want it.

Again, thanks all for the encouraging words

Jeff

cruiser54

You're in good shape my friend.

JPXJMOAB

Not to steal the thread, but what engine will be a plug and play swap for a 95 XJ?

cruiser54

91 to 95.

JPXJMOAB

if I were to use a 96 engine.. What would I all be looking at to make it work?

cruiser54

Treat it as a long block swap and you'd be fine.

JPXJMOAB

ok awesome. I'll be going completely through it and building a stroker .. So I'll really only be using the original block. Everything else including the head will be new.