Rebuilding the engine

Steve Rodgers

TJ Enthusiast
Original poster
Joined
Mar 25, 2018
Messages
355
Location
Maui, Hawaii, USA
My 97 2.5 is long in the tooth, almost 200k. Some day I may be faced with the engine question, the body and frame are in great shape. I would automatically say I should get a good remanufactured engine but out here on Maui the shipping would really be high, both ways.
I’ve done engine rebuilds before, I just did my 1973 Honda CB750 four engine and I have plenty of tools, there are a few machine shops here that could help me with the head and block if needed.
Has anyone done this and are these 2.5’s pretty straightforward? They seem simple.
Get the head cleaned up, valves, guides, seals, etc
Get the block honed, decked, fluxed, seals, timing gear, cam bearings, cam (if necessary), new pistons, rings, bearings etc.
Assemble and paint ( the paint ensures it will run correctly :-))
My other option is NAPA Auto parts here, I suppose they could get a reman, I just don’t know how good an engine it would be.
Any opinions or experiences out there?
No, not interested in the major surgery of swapping in a V-10 from a Viper.
 
You have the option of removing the engine yourself and sending it to a machine shop. Nothing wrong with having your engine re-built.
 
Agree with @TJ4Jim .
The bottom end of these motors hold up great but at 200k you might consider rod and crankshaft bearings.

While you have it on the engine stand, replace the timing chain assembly.

Yes deck the block, and all that and I would consider boring the minimum, 0.010 over then you do practically have a new long block.

The 2.5 is not known to overheat so you should be fine if you want to bore it out 0.010 or more.

You could do it yourself, take pics along the way and try not to lose any bolts or washers and use parts bags with labels and then its just a matter of waiting on the machine shop. :-)
 
Typically the head bolts are a 1 time use, torque to yeld from what I remember. Do you have a bore gauge? Only bore if you have a taper, a good machine shop should be able to do all of the measurements. Assembly only takes a day if you measure everything twice. you may only need rings, bearings, cam, , timing chain, lifters, gaskets, and a valve job. Crank and pistons maybe good to use as is. Pistons are a hypereutetic designe and have very specific tolerances. Tim
 
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Good to know about pistons. If I find myself doing this of course I'd need to research parts availability, such as head studs, bearings, cam, etc.
Thanks all for wisdom.
 
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When the 4.0 went on my Cherokee XJ, I called up LKQ and got a remanufactured crate engine with a 30k mile warranty for $1800.

For that price it made more sense to just pay the money as oppose to rebuilding it myself. I suspect I wouldn't have saved too much, and I wouldn't have gotten the warranty.
 
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