black2000xj

these are things i heard about jeeps, want you guys (and girls) to tell me what you heard

1) It is crucial to let jeep 4.0 motors warm up for a few minutes no matter what temp it is outside b/c the blocks are so thick it takes a while to get everything warm inside
2) letting it warm up will do less damage to the head and headgasket (compared to just getting in and going on a cold motor)

3) just a ?, my 2000 xj doesnt have the cracked head, no milky oil on the dipstick or rusty brown coolant, are thier ways to prevent the head from cracking? i got 140,000 on it, i know they are weak, and if it does go, what do i do? buy a new head?

anyway the first two things are what i heard when i started with the jeep craze about 3 years ago, i never really new the truth, although i do let me vehicle warm up everytime....

let me know what you think about all 3 things

dukie564

1) It is crucial to let jeep 4.0 motors warm up for a few minutes no matter what temp it is outside b/c the blocks are so thick it takes a while to get everything warm inside No but it's always a good idea with any engine
2) letting it warm up will do less damage to the head and headgasket (compared to just getting in and going on a cold motor) Possibly since the oil will flow better around the moving parts when warmed up

3) just a ?, my 2000 xj doesnt have the cracked head, no milky oil on the dipstick or rusty brown coolant, are thier ways to prevent the head from cracking? i got 140,000 on it, i know they are weak, and if it does go, what do i do? buy a new head? Best thing is to keep an eye on the temperature - don't let it overheat, and keep an eye on the coolant level also in case it does crack you want to catch it early. If you do run into the problem the best solution is to get a replacement head, on which they thickened up this area to eliminate the problem

Diesel

Dukie to the rescue.


Immature moment, dukie sounds like dooky.

Spunkmeyer

A replacement 0331 head that's from a 2003-up 4.0L engine is what you'd want to replace it with... the head will have "TUPY" cast into it between cylinders 3 and 4.

dukie564

black2000xj

great, thanks for the response everyone,

now another question is do you know how much a replacement head is, or where do you get one from, junkyard? or order one from somewhere

i just try to do everything in my power to keep major things from going wrong

i just did o2 sensors, new diff fluids, routine oil changes every 2500-3,000 miles
i always believed in preventative maintenence,

just be safe than sorry, would a coolant flush help at all with a new thermostat, it looks like the previous owner put a brand new radiator in in, so i dont think its that old, maybe a couple years or so

let me know about this and the myths i heard

HCCAFan

Fleabay

kemjeep

do the t-stat and coolant change wont hurt and youll know its done

thundaluvin

I would suggest a FAILSAFE t-stat. They are designed to "lock" open at 240 degrees. They are about 15 bucks but, relatively inexpensive when you consider the what happens when a t-stat sticks closed. I have used them in 4 diff vehicles and am extremely satisfied with them.