My Rod bearings are worn similar to an engine i would say with 300K on it.

Ive had this Jeep for 3K and payed a good deal of money for it being the low miles and impressive shape it was in. (Around 4K$)

Here's my story, the oil pressure was low so i dropped the pan and replaced the pump, it made the pressure better but my engine had devolved a rod knock probably due to the rod bearings being worn down to copper.

I was getting frustrated with time so i figured why not have a shop replace the mains and rod bearings for me? I was willing to pay until..

Took it to the shop they figured out the rod bearings were the problem without even opening up the engine( Noise between 4-5). That made sense being its what i said too.
Now they quoted me about $1,000.00 just to replace the rods and mains!

Then they called me up and said i HAVE to get a new engine. So this is where i am now. They have told me that the bearing swap is just a band-aid for the problem that will always come back.

Im not buying a new engine, THIS ONE HAS 83K ON IT!
I have the jeep back at my house.

Now they didnt even say one thing about grounding the crank i honestly dont know if they were going to!

Heres my question, now i just wanna save this motor and not have to swap a whole new one it, i don't know what happened to it but if i had to guess i would say:
-Dirt in the oil
-Heat
-Wrong oil
-Not enough Oil
It has a good head with no cracks and loses no coolant.

So heres the game plan:

Can i drop the crank with the engine still in the jeep and take it somewhere to have the journals ground? If so where can i take it? Machine shop?

Is this really just a band-aid if i have it ground and replace all the mains and rods (with different size rods to compensate for the grounding.)

Thanks guys! If this all works out i will be sure to get you guys a bunch of pictures of all the bearings and stuff.

 

Pulling the crank out with the engine in the Jeep is a nightmare.

Makes me wonder what the cam bearings look like.

This engine probably had bearing damage due to loss of lubrication.

What brand of oil filter have you been using?

 

It came with a fram on it, (i know sucks,,)

Ive used a mobile 1 and a puraltor is now on it.

 

Well, if it's had a Fram on it for a long period of time, it's had dry starts for that duration. Not saying that's it as it could be a number of things.

 

Can you explain the reasons why its such a nightmare? im about to go to college and i just need a good ride right about now and this kinda sucks.

 

Because getting the crankshaft out with the engine in the Jeep and bolted to the flywheel is very difficult. I watched one of my mechanics do it to a 258 on a hoist with professional tools and he said "Never again. I shoulda pulled the engine".

 

I've never messed with the 4.0, but the engines I have worked on,
you have to drop the trans to be able to get to the flex plate / flywheel
bolts that connect to the crankshaft.

 

So this blows.

I might as well just have someone put in a new motor?
:icon _confused:

How much will that run me?

 

Re-manufactured short block is what your looking for try local auto part store also jasper engine company

 

If you know what to look for you can always hit the wreckers and see what they have. You may be able to get a drop in for about 400.00

 

This sucks so much! what if i pulled the engine, removed the crank on the stand then got it ground and did my bearings? The rest of the engine is good and ive already done a leak down test on the upper side.

 

Have you inspected the journals? You may be OK with just replacing the bearings which is easy and inexpensive to do. The soft bearings are what wears first so if it did not go for too long you may be in luck.

 

You can get a reman engine delivered to you for $1600 or so.

 

I second this.
Pull the oil pan and a couple rod caps and take a look. Hopefully you'll find the bearings are shot but the crank only needs minor clean-up.
If you have access to a micrometer you can measure the crank and see if it's in spec. Check several spots on the same journal to make sure it isn't out of round.
If you aren't so lucky, pull the engine, grab a used crank from salvage, take it to a machine shop for cleanup and checkout, and get matching bearings.

 

If you put a new crankshaft in your engine; you'll have to strip it down and haul the new crank and the block in to a machine shop to be line bored.
Line boring mates the new crank to the block.
Not doing so shortens engine life and puts more stress on journals and bearings.