I will make it short and to the point!

2000 XJ Limited
4.0
aw4
np242
non abs
heated seats
factory towing
201,000 miles

Bought from original owner about 30k ago. It uses about one gallon of antifreeze every few thousand miles. When I bought it he just put in a rebuilt tranny all original no wrecks or damage. I have replaced some sensors, ujoints, gaskets the usual replacements parts. It runs very well for the mileage. Has just a slight stumble while idling maybe timing chain, injectors or fuel pump. Out of curiosity I pulled the valve cover to see if the head was cracked. No milky oil, small amount of condensation of out tail pipe. Add me to cracked head club. Talked to original owner and he said he have to keep overflow full. It does not overheat and as I said before runs she like it has 100k miles. Should I spend $500 and replace the head with an alabama head or put in an 06 TJ engine in. I can get my hands on with 30k miles for $1500. I'm a mechanic ace and can do anything under the roof of a car. I'm a Jeep man, pimped commander limited hemi in garage, and picked this up when I decided to throw in the towel on car payments. I plan on doing a lift among other things. I ran seafoam through oil, intake and gas. Runs 10X better and pulled intake and throttle body and cleaned till it looked new and runs like a scalded dog. Would appreciate all comments or questions. For me money is no object just wondering What Would Jeepers Do!

Replace head?

Replace engine if and when it lets go?

Dan

 

If money is not an object and given all the other things you are going to do,i would replace it with a low mile engine,$1,500 for a used motor is a bit much unless you are getting everything attached to it. Being a mechanic you could rebuild yours for alot less than that,Just my opinion.

 

I went and seen the Jeep and it start and runs. It was involved in a rollover. The owner is parting it out. I get the engine, computer and all accessories. For another $1000 I can have the tranny and transfer case. It is a rubi so rock-trac 4:1. I did weigh the option of rebuilding mine. But it is I feel it real hard to turn down an almost new "crate" engine. I also thought about doing a stroker but with the head needing replaced my options are limited to make the replacement crack free and the swapout easy.

Dan

 

rebuild yourself with the stroker... same money... more power... a older head for a 4.0 would be nothing to get ahold of... actually i would just buy a older 4.0 for $200and stroke it whil your other one drives its last miles... that way your jeep isnt down!

 

Then just fabricate a bracket for the coils. I don't want to give up the distrubutorless ignition. I could port and polish the head and intake to port match. What about the header/ manifold. It is my present daily driver but not my only one. I like the idea of buying a nice CHEAP used engine and building it. Would just have the block and head prepped and build it myself. HMMMMMMM

Dan

 

get the intake manifold off a newer jeep... also an exhaust header while your at it... the newer intakes are on ebay alot... i think you may have to do something different with the throttle body then... but ive never done this... just stuff ive read...

 

get the drive train out of the rubicon if you have the money get the axles to they are locked d44s

 

dang that didnt even cross my mind... id get the axles befor i did anything with a motor... lol

 

I had an 2004 Rubi and miss it dearly. I live in Knoxville, TN and anyone in the area knows what windrock is. One of the best offroad parks this side of the mississippiI thought about the axles but I would have to do something about the rear axle since the rubi has coil springs.

 

Decisions, Decisions. If it was me, I would say to myself, self, this engine probably has a good 100,000 miles left in it. So I would do the easy thing and just replace the head. If I got into the block, then I would want more performance out of it if I was going to start spending money on it.

Then with the time and money saved, I would seriously start looking at his drive train, particularly the tcase and axles. Doing all that stuff with the motor, and still having the same one is not time efficient in my book. But to take the time and money and upgrade the tcase and axles and lockers, well that is another story. If I am not mistaken, those axles are pretty much a bolt in for you in the front. The rear would be easy with grinding off the factory hardware and welding on some spring pads.