Just bought a 2000 Cherokee sport. Dark blue with black interior. 4.0L and it has a knock internally from the back of engine. We are thinking its wrist pin, broken cam , or one mentioned possible broken piston. People before us said it ran and they let it sit for 2 months and now it just won't fire. Possibly just bad battery for than problem , but what we are trying to decide is ......... Just replace with running motor OR if Yall know of a common problem with simple fix.... Maybe just a simple rebuild is best.... Trying to get it on the road asap. Any help would be great!!!!! Lovin this forum!!

 

My advice...RUN!

 

I assume you have heard it run? Is it not cranking or not firing?

 

we bought it knowing it had a problem. itll turn over (we got it cheap and its really clean!) but you can hear the knock as the engine rotates. and its not firing. they said it started as a light tick and they just drove it that way for a while and decided to park it as it got louder. Ill post pictures as soon as i can!!

 

run???

 

Sounds like it may have a broken flexplate. I would start by checking into that.

 

bustedback beat me to it, if your auto i would check the flex plate, my XJ developed a knock that i thought was rod knock......but upon removal of my trans i realized it had at least a half dozen cracks spidering from the center varying between half an inch and a couple inches, however i havent gotten the 5spd in yet so it hasnt been run but im hoping that was the cause of the noise.

 

Yea ^. I'd pull the little dust cover on the front of the bell-housing and take a look. Knocking while just cranking.....BUT, if it's just loose bolts on the flex plate there you might be in luck! (they are known to loosen). Guess there where a bunch of bad head castings in 2000-2001 also btw.

 

My 2000 had same problem except it ran. Pulled valve cover found #5 had one push rod bent one off lifter. pulled head had it looked at and like all 0331 heads it was cracked between 3 and 4. Put new head on with all new push rods and lifters. Running great now. Not wanting to scare you but if it was overheated you could be looking at a cracked head and something more.

 

Thanks guys!!! Hopefully we can get it into the shop soon and take a look. It has no rust and two or three smalllllllllll dents.... Oh and a missing stereo that would've been upgrade anyway and 167xxx miles with brand new tires. but for $1,400 I think it was worth it!

 

am i limited to just the engines out of 2000-01?? i was told by somebody who "thought" that was the case but i might have a shot at a lower mile '98 4.0L........

 

You can get the engine from a 98, but it will require fabricating mounts from a coil pack. I'm sure there are some other things as well, but that's one of the things I know from reading different posts on the forum.

 

ok cool glad its doable from different years!!(just in case) I believe the older engine have less HP but when talking 5-10HP I’m not that worried ill stick with fairly new/lower mile engine, "worst case". Wednesday we are going to throw it on the lift and take a look and see where we stand... how do you guys think we did on price of the jeep? we didn’t think it was bad considering the comps. in our area... and we liked the idea of no rust for a northern Indiana vehicle

 

Well we haven't got it on the lift yet but scanner throwing camshaft sensor code. And it turns over but doesn't even try to fire. I did forget to mention its an AUTO and neutral safety switch is bad surprise!!!! but if the flexplate is unharmed , and it has just loose bolts should we just replace the flexplate while we are at it ??

 

Or is there anything else worth taking a look at/replacing while trans is pulled???