I have a 97 cherokee 4x4 its starting to knock bad, I am going to replace the the motor, I was just wanting to know are some years better than others when it comes to the 4.0? mine just turned 160 on the OD any info would be helpful thanks.

 

The 4.0 (AKA AMC 242) Is the best engine they came with, the Engine knock is actually considered normal since it's so common. And no it isn't different over years except the control unit, which was changed when Chrysler bought Jeep from AMC. That's about it from what i know.

 

Whats going bad that is causing the noise? also does it have to be a certian year that is interchangable with a 97.

 

It could be a few things. Most common things seem to be a loose/cracked flexplate or bad lifters, which is what's causing it in my engine.

Can you post a video? There's some people here who could tell you exactly what it is from that.

 

91 to 95 4.0 engines have the best cyclinder heads for flow. 96 was the first year that there was a main bearing girdle to stiffen up the bottom end, and the exhaust ports were a bit smaller. 99 1/2 was the introduction of the 331 cylinder head that is known to crack.

 

There are noises that you can safely live with and others you can't. Can you post a video?

 

Thanks guys i will post a video

 

tried to upload video, am i doin something wrong?

 

i save mine to u tube then copy and paste

 

If you have a 97 I would replace it with a 98. You'll still get the stronger head plus you wont have to modify the ignition ('00 and '01) have the coil on plug ignition instead of a distributor plus the 98's put out a few extra horses versus the 96 and earlier plus before 96 they used OBD I instead of OBD II so your PCM wouldnt work and you can probably find a 98 with a decent amount of miles on it. That's my take on it

 

Thank You!!!!!!!! information like that to someone who doesnt know is a big help

 

http://www.youtube.com/watch?v=zBI7l...ature=youtu.be
sorry the video sucks

 

That's not a "safe to ignore" noise. Either loose flexplate bolts, or rod/piston skirt trouble.

 

Oh crap, yeah that's bad. You were talking about an engine swap, yes?
Honestly i would try to fix it rather than replace the whole thing.

 

Sounds like a broken flexplate to me.