1991Jeep_Man

I want to get a new 4.0 for my 91 XJ. Mine has almost 200k miles, still runs great (mostly ) but I want to have a rebuilt one ready when this one decides to depart for Jeep heaven. My question is this..

1) Should I just save up, and order a new enginer from Jaspers or somewhere like that?

or

2) Should I go to the local Junk Yard, grab a 4.0, and rebuild it?

I am a novice mechanic at best, however I have an uncle who knows cars left and right I can get help from. And I have a Haynes Manual and can usually put something together if the instructions are in front of me.

If people suggest grabbing one from the JY, should I get a 91 4.0 or try to grab a later year 4.0?

Thanks for the input everyone

1987 new toy

You have two problems with that question, 1 most places that sell engines are going to require a core block and can charge 250 or more for that core so if its going to sit around just waiting for the other to blow up it's going to cost you.


2.junck yard engines you need to make sure it turns over through all the pistons revolutions. If not it could cost you a lot of money in a crank or rods, The main prob is it could have a cracked head an sometimes you cant tell untill it goes to the rebuild shop and the magna flux it for cracks.


3. also unless you have a shop rebuild it for you and surface the head and block and do a complete head job, your not really in your garage going to get the reliable of a rebuild doing it yourself.

Most of the time you can buy one done for the same amount of money that you would have it rebuilt for.


Just some things to look at.

1991Jeep_Man

Hmm... I like your advice.. So basically, the best thing to do is just save money, and when it does start to go, buy a new one. Besides, half the outer stuff on my 40 is new with lifetime warranty (water pump, harmonic balancer, power steering pump, etc...)

fishtaconc

cost wise like stated itll be about the same (if you dont count your time) to buy a reman or rebuild it yourself so it really comes down to if you would feel better doing iot yourself, also one important thing to consider is if you buy a reman then you get a warranty from the company if you doi it yourself you warranty it yourself . nothing wrong with either choice like
I said it comes down if you would feel better buying or building

1991Jeep_Man

Great point. My final decision is to just hold out and put some money away every now and then, and when the motor starts going bad (which shouldn't be for sometime), then I will order a reman. Besides, when I order a reman long block, all I gotta do is hook all the pulleys and hoses up to it don't I?

1987 new toy

yep intake exhaust and wiring. Besides depending on what you do with it and how well you take care of it, it could go another 100,000 or more.

1991Jeep_Man

I'm hoping so. I try and take care of it as best as I can. Top notch oil every 3000 miles/ 3 months. Recent tune up. Everytime something starts to go, I try and fix it before it gets bad. About to drop a new radiator into it, Lord knows how many things I have replaced in the 8 months I've owned it.