I have a 98 jeep cherokee 4.0 with the ax15 transmission. Its got 276k on it and still going fine. The only issues with it are a small rear main seal leak after sea foam, a rattling cat which is about to be replaced, and the cooling system inside the motor is rusted but ive replaced the radiator and flushed it to clean it up some and its now mostly clear green instead of foggy brown. Its a little noisy im guessing its the valves and lifters but its got me thinking about a rebuild. Ive never done a rebuild on a vehicle just dirtbikes and small engines but with the right tools i believe i could do it. I just need some advice on whether to rebuild it or get a remanufactured engine in it. I want to to go the cheapest route. My main questions if i rebuild it are 1/ Will i need to have anything done to the cylinders before installing new pistons? 2/ What all do i need to do to the head to make it like new again? 3/ Would i have to do anything to the crank? Any answers, info, or advice is much welcomed as im sure it will help me out alot. Thanks.

 

Poteat Engines in Kannapolis will rebuild yours for a thousand bucks and give you a 2 years/24000 mile warranty. IMHO that's tough to beat. They did BiL's Nissan and my 4.0.

http://poteatsengines.com/

 

If it ain't broke, don't fix it. Depending on what kind of time you have, you could buy another used engine rebuild that one and swap out when and if the old one ever dies. You are right to think ahead with that kind of mileage on your old beast but fluids are clear, it starts most of the time... what else is there? Buying a rebuild already complete that comes with a warranty is hard to pass up. I rebuilt mine myself (4.6 stroker) and spent as much as buying one finished . Just depends on what you are looking for and how much effort you plan on putting into it.

 

Rebuilding your engine could open a whole can of worms, and sometimes you'll be into enough to have bought a rebuilt engine, and realize that you have to spend even more time and money... If you had your own full shop, maybe, but otherwise I would not.

 

It doesn't sound like you are quite ready to do a rebuild. I myself do some things with heads, but just taking it to the shop is the normal route. Just grinding the valves and changing the seals is all. Maybe make it flat if it's warped.

You could save that head and use it on another motor if you want. First, like said, clean up what you have and see where to go. One of mine is fine and strong at 280K, Even gets 22 MPG on the highway!

If local wrecker had something with 150K or so for a few bills, that is what I'd probably do, if one of these actually goes!

 

x2 On the if its not broke dont fix it,

Ron

 

Yeah im not gonna touch it till i have to im just wanting to get a idea of what will be best for me to do when it does. That rebuild with the warranty sounds pretty good though and hopefully itll be a while before it needs it.

 

Fix the little things and do a few minor upgrades to help you keep enjoying your rig. This might be a new stereo or some wheels and tires or other interior cleanup/modifications.
One thing I do is keep a complete log of repairs and a folder for ALL repair/modifacation parts. The parts folder comes in real handy for the second or third time a part fails. Like oil pressure sending units. Im on the 4th or 5th. Only takes a few minutes to change and NO insult having to repay for the part.
Next have a fund started for the project, This allows you to buy the replacement if or when it fails. Having the money sitting in the bank or an envelope in a drawer will help you feel more confident. It also my make you think that for X amount of dollars I can find a nicer Jeep. Some people want to swap vehicles often. Some people are happy keeping an older rig with the pride you have extracted every mile it has to economically give. The repair log lets you see when a repair had been done or is due next time. Helping keep track of every dollar spent. Wise or not!
I myself am sure I will stay with the XJ, TJ or maybe ZJ platforms. So extra parts or ones purchased with a lifetime warranty will be saved/ hoarded. I have some storage space to do this. Also at least one of my 5 children also at any given time has a Jeep.
No one Id rather share parts with.
I also keep a spare daily driver to rotate the 95 mile round trip to work daily. This makes it possible to take a vehicle out of service if it has the smallest problem. I dont have to make a repair if Im not up to it. My dailys are at 235K and 238K as of this weekend, I would not feel uncomfortable driving cross county in either of them any time.
For me (a cheapskate) the thrill of driving a high mileage, reliable, safe and good looking car is great.
You are right on track keeping an eye on it and having a plan if one is needed. Good luck hitting 300K which is my goal on the beaters Ive got.

Ron