Jeep Help needed Cherokee XJ with spun rod bearing

[Homefryy]

I have a 96 Cherokee with 162k miles on it. I have only owned it for 6 weeks. It developed an engine knock about a week ago. I stopped driving it as soon as the knock started and trailered it home. I ended up dropping the oil pan and discovering that the connecting rod bearing for cylinder #4 was shot. I pulled the remaining scraps of bearing off and the crank journal is pretty rough. My understanding is that I will need to remove the crank and have it machined and I have a few questions about this I am hoping I can get some help with.

Everything else in the engine looks pretty good as far as I can tell but I am not an expert on engine internals. Should I just get the crank machined and replace the bearings or have somebody do a complete engine overhaul/rebuild? The other option would be to swap in a junkyard or re-manufactured engine. I would like to save as much money as possible (trying to save for a lift) but having a reliable vehicle that I can take on long road trips and adventures into remote areas is important. I am willing to spend the money necessary to achieve that. I can pull the crank and or engine myself to take to a shop or swap out.

Does anybody know of any good engine machine shops in the Salt Lake area that you can recommend?

Should I be looking for something that could have caused the bearing to go out like oil flow? The Jeep has the basic gauges with idiot lights so I don't know what oil pressure was before or after the knock started. The engine had fresh oil when I bought it roughly 1,000 miles ago and didn't use any in that time. The Jeep did overheat once approximately 300 miles before the knock started. Not sure if that could have caused it or been related or not.

Anything other advice or things I should consider?

Here is a picture of the journal on the crank.


Here is a picture of the bearing fragments.

 

[rholbrook]

Sell it to me

 

[mbryson]

If it were mine, I'd find a good used engine out of another similar year XJ and swap it. If that got frustrating and I was pretty married to the Jeep, I'd rebuild it. Hope things work out for you

 

[thenag]

If it were mine, I'd find a good used engine out of another similar year XJ and swap it. If that got frustrating and I was pretty married to the Jeep, I'd rebuild it. Hope things work out for you

Frustrating...

Not all 4.0l blocks interchange, so you will need to do some research on figuring out exactly which ones will interchange. Check KSL you might find something for a few hundred, I think I sold my engine for $400 about a year ago.

I don't know if anyone has had long term success on just replacing bearings, I guess you could have the crank ground, install all new bearings, I don't know why that wouldn't get you back on the road. I am the type of guy that at that point I rebuild the engine anyway because I am almost 1/2 way there (labor wise, not really $ wise)

Why did it overheat?

I have never used them but Crankshaft Grinders is usually one of the places recommended on here. I got all my stroker stuff and machining done at Clegg in Orem.

Nathan

 

[04F150]

I have a rolled 96 xj with a good motor and trans I would sell cheap

 

[spacecase]

several years back i had a chevy big block begin to spin a bearing. it wasnt hard in my situation, i just pulled the crank, had it turned and matched it with a new set of bearings.

i think mine was caught early, before it had a chance to fully spin and damage the journal.

having my crank simply turned was considerably cheap considering i did the tear-down/install myself.

in your case however, with the bearing journal being damaged, you would need to have the bearing and journal honed and bearings matched to not only the over-sized journal but the turned crank as well.

at that point, you would need to pull the motor and send it to a machine shop.

look into the cost of the job, you may find its worth the risk of finding a donor motor to swap and save some cash.

or, if i had the money and planned to keep the rig.. do a complete overhaul and re-install.

my 2 cents, for what they're worth.

 

[mbryson]

I have a rolled 96 xj with a good motor and trans I would sell cheap

That's something I'd look at pretty seriously if this was my XJ with the bad motor

 

[spaggyroe]

Revised to go along with the voices in my head.

That's exactly what I would do if this were my XJ with the bad motor

 

[DaveB]

I have a rolled 96 xj with a good motor and trans I would sell cheap

My nephew's XJ has a rod knock, how much for it ?

I have a low mileage 4.0 crank sitting in my basement if you wanted to use that to put in your Jeep. I think the jeep had about 70K miles on it before it was wrecked. I bought the jeep for the motor but found that the block was damaged so I pulled out all of the internals and they have been taking up space ever since.

 

[BCGPER]

At a bare minimum, you'll need a set of main and rod bearings, at least one new connecting rod, a crank grind, new oil pump, and a complete gasket set. That'll get you back to your 160k original engine. I'd be all over that used engine, it's a no brainer if it'll work.

 

[UNSTUCK]

Roll a bearing in and plastiguage it. If it's at all close run it.

 

[04F150]

My nephew's XJ has a rod knock, how much for it ?

I have a low mileage 4.0 crank sitting in my basement if you wanted to use that to put in your Jeep. I think the jeep had about 70K miles on it before it was wrecked. I bought the jeep for the motor but found that the block was damaged so I pulled out all of the internals and they have been taking up space ever since.

$400

 

[Homefryy]

I have a low mileage 4.0 crank sitting in my basement if you wanted to use that to put in your Jeep. I think the jeep had about 70K miles on it before it was wrecked. I bought the jeep for the motor but found that the block was damaged so I pulled out all of the internals and they have been taking up space ever since.

How much would you want for the crankshaft? I may be interested in that.
I've been looking into re-manufactured engines and so far I haven't found a company I feel super comfortable buying one from. All I read about online is people with engine problems and the companies not wanting to honor the warranty. It is hard to say though since people who have no problems don't tend to start threads letting everybody know that they haven't had a problem with their new engine.
I'm thinking that I may just do a full tear down and rebuild myself with the help of a local shop or buy a used engine that is in good shape. I'm having a pretty hard time making a final decision though. I'm currently working on sourcing an engine hoist and stand since no matter what I do the engine has to come out.

 

[DaveB]

How much would you want for the crankshaft? I may be interested in that.
I've been looking into re-manufactured engines and so far I haven't found a company I feel super comfortable buying one from. All I read about online is people with engine problems and the companies not wanting to honor the warranty. It is hard to say though since people who have no problems don't tend to start threads letting everybody know that they haven't had a problem with their new engine.
I'm thinking that I may just do a full tear down and rebuild myself with the help of a local shop or buy a used engine that is in good shape. I'm having a pretty hard time making a final decision though. I'm currently working on sourcing an engine hoist and stand since no matter what I do the engine has to come out.

You can have it for free, I have way too much junk in the basement. I just need to make sure I don't get rid of the 4.2 crank my son has for a stroker build.