2000 grand cherokee 4.0 compatible?

[brownscampmj]

so i found a core motor that came out of a 2000 grand cherokee it is the 4.0 inline 6. are the manifolds compatible with my 88 mj which is also 4.0 inline 6

? i would think so but i don't want to spend the money and then have it be wasted

[87Warrior]

No.

 

The motor mount bracket bolt locations are identical between a TJ and WJ but not the XJ and MJ.

 

The MJ motor mount brackets will not bolt onto the WJ block.

[brownscampmj]

I'm not taking the block at all. i work at an autowrecking yard. i seen the 4.0 and told em not to scrap it. all I'm looking for is those manifolds. it would be a good headstart on porting and polishing them out before putingthem on the mj. having that cleared up do you know if the manifolds are the same?

[richasco]

The manifolds are different. They will only bolt to a High Output head, although some people have been able to get them to work with some grinding. Your fuel injection will not bolt on without work too. You could grab the head and bolt it and the manifolds to your engine. Make sure you research "0331 heads" first, that 2000 head is likely to crack/already cracked if overheated.

[brownscampmj]

alright good to know thank you . :MJ 2: .

[Motorcharge]

It's not just the motor mounts that are different, the block is different entirely as are the setups for the engine accessories. The 0331 head issues are seriously blown out of proportion on forums though I wouldn't swap one in unless it was free. Head swap on a 4.0 can be done in 4-6 hours pretty easily and aside from a torque wrench you only need basic hand tools. Very simple since you can pull the head and manifolds as one piece. Well you can on an XJ/MJ, not sure if the engine bay is big enough to on a WJ. I did my first one in about 7 hours having never done one and the only time I even looked at the manual was for torque specs. I've flipped a few 00-01 XJs since after replacing 0331 heads and I can do them in about 3 hours now as long as I have someone to help lift the head an manifolds because they're heavy as hell if you pull them as one piece.

 

As for the 0331 heads, they're a defective casting. They're prone to cracking between the 3rd and 4th cylinders if you get them too hot from overheating. But like I said before, the issue is widely blown out of proportion on Jeep forums due to people parroting information they've read. You'll find far more people complain about the heads than people who actually had issues. It's not like the 4.0 is made of aluminum, they're iron so even the defective heads you have to overheat pretty bad to crack them. Even then TUPY heads are readily available and several manufacturers make aftermarket replacements for a couple hundred bucks. The effected heads are on 00-01 XJs, 99-01.5 WJs, and 99-01.5 TJs. Some people claim up to 06 but the casting was moved to Brazil for the 02 model year and the issue was addressed but they didn't change the casting numbers.