2000 XJ with bad motor

Hello everyone.

I'm new to the board and I have a 2000 XJ that has had a rough life. It gets about the most abusive type of use: NYC commuting. About a week ago the engine seized. The jeep had done well until this catastrophy. I use it to get to work and I need to get to work no matter what. It has never let me down in deep snow, water, potholes, sinkholes, construction plates, traintracks, etc.

I'm deciding whether to fix it and sell it (probably then pick up an older xj) or fix it and keep it.

Just wondering if there is anything I should know about this model year that would help me make my decision.

Thanks.

P.S. How do I get my own avatar?

Welcome to Naxja. the 2000 and 2001 xj's had the 0331 head on the motor. use the search button at the top to search "0331 head" and you will see they are prone to cracking (since you just joined you may not have known about it hence i am kindly pointing it out ). if you are looking at replacing the motor, you could use a different head or entire different motor from an older 4.0 but you will then need to do your homework on how you want to go about the electronics (the 0331 head had a distributorless ignition that no other head had mounts for so you will have to fab something up). You can replace it with the same 0331 head but then you are taking a risk on it. Search the forums and you'll learn plenty to make a more informed decision on whether you want to keep or sell it. A lot of the things to look for when buying a new cherokee include stronger axles (chrysler 8.25 vs dana 35's-and high pinion vs low pinion d30's in the front... probably not a big deal for you since you didn't say you wheel it) factory limited slip differentials for better onroad traction (trac lok). I am guessing this is enough material to start you off. To get your own avatar you have to become a member and pay your dues. Again, welcome to Naxja and feel free to ask more questions, but make sure you search the topic first because a lot of guys will get upset answering questions that have been answered before.

Thanks, that was about what I was looking for. Its never easy being the new guy. I'll start my research. I wasn't aware of how much history is kept on this site. I would have thought it gets purged but there seems to be a ton on here.

Thanks Again.

I have an 01 xj and this is news to me. Ill have to monitor that.

What exactly happened to it? Did the motor lock up due to coolant and oil mixing together?

Welcome to by the way. My Jeep also came from NYC....somehow made its way down to NC and into my hands.

The head cracked (apparently very common). I replaced it with a reman head. About 3 weeks later on highway oil pressure bottomed out and engine heated up (sounded like it was running fine though). I pulled over to give a peek and let the engine cool. I kept the fan running and shut the motor down. After about 20 minutes I tried starting it up and nothing.

I had it towed by my mechanic. He looked at the top end and it looked fine. On the bottom though things were bad, the crank was stuck solid and cam would not turn.

That's where I stand now kicking myself for spending money and changing head to get an extra 400 miles before engine died.:smsoap:

There are plenty of U pull it salvage yards upstate. Gary's in Bing comes to mind. Motors are $155 w/core, and if you can pull a head you can definately pull a motor. All you do is unhook everything and they will come down with the loader and put it onto your truck/trailer. Jeep cherokee's all day long. iratefla

If everything else on the jeep is good drop another engine in it. You know the history on this one, and after you swap the engines you'll know a lot more. I have a 2001 and replaced the head after it cracked, though there are a lot of 4.0 L engines from 2000 and 2001 that didn't have this problem. Do what you can to keep the engine cool and happy with synthetic oil of the right weight for the season, and think about improving the coolant system (use the advanced search engine here) High flow water pump and thermostat, tranny oil cooler if yours doesn't have one stock, and keep the fluids changed. JMHO.

You should find out what happened to kill the current engine. Could have been an oil pump, litter getting into the engine or head during the swap, ginormous oil leak, and on and on.

Good luck, but remember it's just a car, not a space rocket. Pretty simple for the most part and nothing to be intimidated by.

Fish'nCarz said:

You should find out what happened to kill the current engine. Could have been an oil pump, litter getting into the engine or head during the swap, ginormous oil leak, and on and on.

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He said the head was cracked so my guess is that the oil was contaminated with coolant and this reduced its lubricating ability. The result was rapid wear of the rod/main/cam bearings and a seized engine.

Yeah, if he drove short distances and didn't change his oil often that could happen. Short commutes are the death of lots of engines that otherwise would have lived long lives. If I drove lots of city miles I'd probably go to 2,500 miles between oil changes.

Depends on whether you want an unknown motor out of a yard or a true rebuilt one with a warranty. I had a new jasper reman dropped in last year, my old engine lasted over 330,000mi in my 98. The new jasper came with a 3 year, 70K warranty. Total cost was ~$2500 installed and included new hoses, water pump, tstat and a whole bunch of stuff down to and including a new pressure cap. I don't ever plan on getting rid of this one. I work in the trinity building on broadway and now use the train out of morris plains and path out of hoboken to commute. I only drive 7mi one way in and 7mi back then 62mi home to pa on friday and 62 mi back in sunday nite, going to a 2,000mi oil change interval next week.

Thanks for the input everyone. This site is great! Too bad I didn't discover it earlier. I have done extensive reading on the site and have decided to replace the engine with a reman with a warranty. I will have my mechanic do the work as time is tight right now and my skill level is not that high.

I will also be following the lubricating tips from a lot of the other threads once the truck is running again.

Thanks again for the info and tips. Now on to more reading about what engine to drop in there.

If it was mine I'd stick with a stock engine because of all the electronics and OBD II system. If you change engines you'll have a lot more to mess with. Again, JMHO. And you'll never get better or hotter spark than the system on the 2000 and 2001 4.0 L I6, and you never have to worry about plug wires, distributor, etc. either. If you get a reman with a good warranty I wouldn't worry about the head casting too much. Keep it running cool and worry about it even less. It's a machine, they all break down eventually somewhere.

Oh, and I've heard that you don't want to run synthetic oil in it until after you complete the break-in period. Apparently some level of friction and wear are necessay in a new or newly rebuilt engine. FWIW.

RichP said:

Depends on whether you want an unknown motor out of a yard or a true rebuilt one with a warranty. I had a new jasper reman dropped in last year, my old engine lasted over 330,000mi in my 98. The new jasper came with a 3 year, 70K warranty. Total cost was ~$2500 installed and included new hoses, water pump, tstat and a whole bunch of stuff down to and including a new pressure cap. I don't ever plan on getting rid of this one. I work in the trinity building on broadway and now use the train out of morris plains and path out of hoboken to commute. I only drive 7mi one way in and 7mi back then 62mi home to pa on friday and 62 mi back in sunday nite, going to a 2,000mi oil change interval next week.

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I worked for a city parks department for several years and the motor pool mechanics always changed the oil at 2000. They maintained it was the single most important thing they could do, aside from keeping idiots from driving "their" vehicles!

Thanks Fish'n that's probably what I'll do. I hadn't heard about not running synthetic at first, but it sounds plausible. Once I get the Jeep going again I will be right on top of the oil changes because of the abusive driving style.

I used to change oil every 3,000 miles but sometimes that was 4 or 5 months. I should have seen this coming; the old oil in those oil changes looked like it had been running for 10,000 miles.

Now I will change it about every 90 days, worth it in the long run as I will need many more years out of this truck.

Since you do a lot of short distance driving, I'd definitely suggest a good synthetic oil....my favorite is Mobil 1 10W30.

99XJSPORT06 said:

Since you do a lot of short distance driving, I'd definitely suggest a good synthetic oil....my favorite is Mobil 1 10W30.

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Walmart has the 5 quart containers for like $21 or $22, then I just buy a 6 pack at the same time. I also normally buy 6 of those 5 quarters when they have them on sale. All our jeeps use them then theres the wifes 5W30 oldsmobile, sheesh...the odd ball that takes a different filter...

Well the new engine is in. The oil pressure is still low at idle (according to guage). I have the standard oil filter on there now. I've had the truck for 4 years and never had the guage dropping until right before the motor went, so I am concerned about it being low with the new motor.

I may put it up for sale (and get an older XJ) because of the damage to my wallet. I'm going to my tax accountant today and that will clear up the picture a lot depending on refund $

Thanks for all the previous tips, I figured I'd throw in an update.

NYPDJeep said:

Well the new engine is in. The oil pressure is still low at idle (according to guage). I have the standard oil filter on there now. I've had the truck for 4 years and never had the guage dropping until right before the motor went, so I am concerned about it being low with the new motor.

I may put it up for sale (and get an older XJ) because of the damage to my wallet. I'm going to my tax accountant today and that will clear up the picture a lot depending on refund $

Thanks for all the previous tips, I figured I'd throw in an update.

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How low is low? Mine drops to around 15 or so at warm idle and around 40 at highway speeds. I think that's within the normal range.

I have 700 mi. on my 2000 XJ after swapping out an 0331 cracked head(@100,000 mi) with a reman 0630. So far so good for me, and I feel your pain. I caught the crack right away and am not too worried about bottom end problems. I agree about swapping out engines. Even $3500 bucks will not buy you a different '00 ride with a fresh engine. Its a good investment!