I have a 00 xj, just got it, putting a new jy engine in it, 109xxx on the one going in 175000 on the one coming out with the cracked block...i have read alot that these heads are prone to cracking...if i put a 2 or 3 core rad, heavy duty water pump...low temp t-stat, flex fan on this...do you think that would lessin my chance of killing the head...I have heard you can swap the head from an 02 or newer grand cher, but I'm kinda on a budget so...im just looking at all my options. You know i have read alot of threads on here about the heads being bad on the 00, is there anyone out there who has one that hasn't had any issues with them. This engine looks clean on the inside...valve cover looked like it was brand new inside...no crust or caked up gunk....whoever had this engine took care of it...(the one im putting in that is) the one that i took out was caked in crap...filthy nasty sludge...but it had set for a year so...I don't just trying to figure out the best route to take to insure the life of the engine, and my new toy. Let me know what ya think...thanks in advance.

 

You can try to do everything in your power to prevent it but it will most likely still happen,just get yourself and aftermarket head that states it has fixed the casting problem, all heads from late 99-01 are very likely to crack sooner or later.gl

 

I would install it as is for now and save up for a updated 0331 head from Alabama cylinder head or clearwater cylinder head and swap it when its convenient ..... CW sells on ebay. I would not trust a "rebuilt" 0331 from a local cyl head shop as most check the combustion chambers for cracks. The 0331 doesnt crack in the combustion chamber. It cracks on the top of the head letting coolant slowly seep into the oil which in turn wipes out bearings leading to low oil pressure.
Upgrading to a 3 row or other things wont stop one from cracking. its a casting flaw, not one usually brought on by running hot.

I have a 01 with 204k on it with the original head and no problems but I had a 00 with 160k when it starting using 1 qt of coolant a week.... some last, some dont.

 

Hey Rmart how about you come off one of those xj lol no wonder i only found 2 on CL...because you own the all the others lol