250kcherokee

I have owned a 1992 and 1994 cherokee 4.0, great reliable vehicles both with 200k+ miles. I sold them a couple years ago but now am soon acquiring a 2000 model cherokee 4.0.

I have heard some horror stories about these newer models, and I am willing to anything I must to prevent these failures.

I hear alot about minor electrical problems, these do not worry me. So your speakers and door locks stop working, not a heartbreaker.

The issues that worry me involve the cooling systems. I have heard of blown head gasket, alot of overheating, cracked heads, radiators boiling over, etc.

My current plan of action is to replace the thermostat, water pump, maybe flush coolant, install coolant filtration system maybe, and a radiator if you guys think that is a must.

Another issue I am hearing is the fuel pumps fail around 100k. This was infront of the tank on my 92, but i hear people saying you need to drop the tank on a 2000 to replace it? I haven't inspected it yet.

I also plan to do the normal jeep fixes like the oil filter adapter o-rings, motor mounts, valve cover gasket etc.

Any other things I should know with my upgraded model year?

Also would love any tips to prevent rot on this currently rust free jeep. I was thinking of getting internal frame coating that I have read about and spray inside the rockers and unibody frame rails.

Thanks alot for any input, hoping the new ones are just as good as the old ones!

Bustedback

Replace the radiator, water pump, thermostat and housing, fan clutch, and all of the hoses. That is cheap insurance on any used car. The tank does need to be dropped to do the pump on 97 and newer XJs. You may not have to worry about the valve cover gasket, the later model engines had way better gaskets.

DFlintstone

"The heads that had trouble were the early #0331 heads (1999-2001WJ/TJ, 2000-2001XJ) before they were revised in late 2001 (revised heads have the "TUPY" foundry mark.)" I'm told that "TUPY" mark is visible through the oil filler.

I suppose I wouldn't be as worried that an 0331 will crack, as I would be that it did, and someone it selling it. Often right in the middle, between 3&4. People have seen a green line of coolant, or deposits/staining, whiteish, right under the oil filler. In any case, you definitely do not want to overheat one of those!


The booger is once the coolant gets into the oil it starts reacting/eating the bearing surfaces. Draining the chocolate milk oil and installing a new head only works if it's caught fairly soon. You should find plenty searching that 0331 head.

250kcherokee

Thanks guys. I did check the dipstick of course and there were no signs of coolant in the oil. It also ran great with no signs of head issues. The motor looked dry. I will have to inspect this further. If there any way of preventing the head failure?

tjwalker

The only thing you can do is to be sure that your cooling system is at 100% and that often means all new parts. Cooling system parts aren't that expensive if you do the labor yourself. Also be sure to keep a close eye on your coolant level (check weekly) as "unexplained coolant loss" is one of the primary symptoms of a cracked 0331 head.

There is no way to guarantee your factory 0331 head won't crack. I've seen XJs with great maintenance and no overheats suffer the 0331 crack.
Will all 0331 heads crack? Absolutely not. But enough do to warrant significant attention if you own an 00-01.

What you do need to know is that an overheat and poor cooling system maintenance will definitely increase your odds of having a head issue. That's why you need to be up to snuff on your cooling system.

Good luck!

extrashaky

Mine cracked with no overheats. If I were buying another one with the 0331 head still in it, I would just go ahead and plan/budget to replace the head with a more reliable one. But that's just me.

extrashaky

A few other things you may want to know about the 2000:

In 2000, with the end of production in sight, Chrysler was running out of high pinion front axles and had a bunch of low pinion axles in stock, so they switched over to low pinion. That can cause clearance and drive shaft issues if you're planning to lift the vehicle. A lot of people switch over to a HP front axle.

Also in 2000, Chrysler was very confused about emissions and made at least two versions of the exhaust that year, a 49-state "EPA" version and a "California" version. The EPA version has a regular mandrel-bent y-shaped downpipe and a single catalytic converter at the rear of the vehicle, with two O2 sensors. The California version has a y-shaped downpipe that has two additional catalytic converters in it (total of three), along with four O2 sensors. (In 2001 they went to the catted downpipe for all models.)

Because of the way they designed it, your options for both models are limited somewhat if you want to do anything with your header or downpipe, but more so with the California version. Prior year headers will often not fit these vehicles without modification. Direct fit options are limited. Keep in mind that you'll need to do your research before modifying anything there.

The late model versions have the window washer bottle inside the driver side fender. You may need to relocate it if you plan to add a snorkel.

The earlier models had a square hole cut in the panel directly in front of the airbox to allow cooler air to pass through from the grill. I don't know when the change was made, but the later models do not have this hole, so airflow is restricted to the hotter under-hood air. Apparently some of them even have a pipe that wraps around the side of the airbox to take hot air from next to the exhaust manifold. These engines benefit from a cold air intake.

I'm sure there are some other peculiarities I'm forgetting.

250kcherokee

So I have the cherokee in my possession now and have looked it up and down pretty well.

To my disappointment I discovered three cats! Are these years doomed for the quest of more power? I do need to pass emissions in my state.

It also has the low pinion front axle.

However, the good news is that the head has no syptoms of being cracked, and I ordered all new parts for the cooling system and will do a full flush asap.

DFlintstone

And you got him down to....

Fred/N0AZZ

Rest easy for awhile and take things as the arise, as I've gotten older I live my whole life that way its much easier. Most all of your problem areas can be sorted out with a little time and labor with a 97-99 parts XJ 99 being the best for you and have everything you need.

extrashaky

You have the California emissions version. You're not doomed, though. The Banks Torque Tubes header is a direct fit replacement for the stock manifold and comes pre-drilled with the bungs for your upstream oxygen sensors. It will work with your stock precats. There are also some cheaper knock-offs of the Banks header floating around, but I can't speak to their quality.

If you're willing to spend some fairly serious coin, you can replace the stock catted downpipe with a Magnaflow downpipe with free flow cats. That thing is about $700, though. I really have my doubts whether any gains would be anywhere near worth the money. Unless your existing precats have a problem, I would leave them alone.

Other than the precat downpipe and extra O2 sensors, the rest of the exhaust system is pretty much the same as the 49-state version. You can replace the rear cat with a high-flow model fairly inexpensively, and you can put a cat-back exhaust on it.

My own setup has Banks Torque Tubes running into a stock 49-state downpipe (no precats), both of which I had ceramic coated by Swain. I have a stock crossover pipe (which I will probably have ceramic coated at some future date), then a Magnaflow high-flow cat and a Gibson stainless steel exhaust that I absolutely love. The only part of my setup you couldn't do is to coat the downpipe, since the heat would likely screw up your precats. I doubt you would experience any hit to the performance compared to mine. And having the precats wouldn't have any effect on any other performance mods you might want to do.

Regarding the tendency of these things to crack their heads, I would suggest sending oil samples off to Blackstone or a similar lab to see how the engine is wearing. If you have any head problems, the evidence will show up in the oil analysis before you can detect it through conventional means. It's a cheap ($25+shipping) and fairly easy way to detect problems early so they can be fixed before they turn into worse problems. I send samples off at every oil change for both my vehicles and probably will never do another oil change without an analysis. Some people balk at the extra cost, but I think it's cheap peace of mind.

salad

In addition to the EXCELLENT stuff in this thread so far, if the fuel injectors and intake manifold don't appear to be insulated now, plan on getting some heat wrap for them. On hot days the heat thrown by the pre-cats can boil fuel in the injectors while the Jeep is parked, causing some rough running when you fire it up again. This heat soak doesn't show up on every 50-state XJ but as the cats age it'll probably appear eventually. Plus shielding the intake from all that heat is a good thing.

250kcherokee

Some great exhaust info! I will definitely take note.

My 4.0 does have the foil heat shield on the intake manifold.

So far I already installed a new waterpump, high flow t-stat and housing, and flushed the system. Took the valve cover off too, the head is good as of now.

Also discovered I'm victim of the common electrical problems. Passenger side window switch and speaker don't work. No biggy, I'll get to them when I install my stereo.

extrashaky

This just came up on another thread. The stock speakers in these trucks like to just rot away. Most people assume they have a wiring problem until they open the door up and see that the diaphragm is basically gone. I'm not saying your wiring isn't screwed, but check your speaker first.

The stumbling block in replacing them is that the stock system's impedance is 2 ohms, while the overwhelming majority of replacement components are 4 ohms. You'll have to keep that in mind when replacing speakers or rebuilding the stereo system. If you keep any of the 2 ohm speakers, the impedance mismatch will burn them out if you install a 4 ohm head unit or amplifier. You can reuse the wiring if it's intact, but pretty much everything else has to match, and the selection of 2 ohm speakers is quite limited.

I had been trying to replace individual pieces of mine, but I've pretty much decided on a complete replacement at this point. Which brings up another fun problem, which is that there are virtually no 1.5 DIN head units that are a direct fit for the original hole in the dash. You can't put a 2 DIN unit in there without hacking holes in the ventilation system, and the single DIN units leave a gap that you have to fill with a mounting kit. If you replace your head unit, you'll probably want one of these:



I have the Limited with the overhead console, and I've actually been kicking around the idea of relocating a single DIN head unit to the unused garage door opener area above my head and putting a Galaxy Note in the hole in the dash to control it, but I haven't worked out exactly how to accomplish that yet. It may be more trouble than it's worth.

250kcherokee

I bought an install kit to take up the extra space, it doesn't bother me. I'm installing a sony head unit and replacing the factory front speakers and wiring.