rule out 2000+ when buying?

[joe_peters]

So...from what I've seen you can replace the head, and the axel? Im not super "mechanically savvy" yet, but I just bought a 2000 with 125K, not knowing about these "issues". Would def like some info. Thanks!

The axle, other than having the low pinion which can drag on rocks, really isn't a problem--just a D30 of a different "color".

You could swap the front axle out if you want, depending on how hard and what type of wheeling you do.

If memory serves, the 00-01 can be a little fussy with vibrations with some lifts.

 

[Milford Cubicle II]

I'd buy a 99 before a 00 given them being in the same condition... a rust free, straight chassis trumps all though.

00 federal emissions is pretty easy to swap to a 99- head/exhaust without getting a CEL or having any real problems, since they have the same old o2 sensor setup and no precats, you just bolt on the earlier parts and do a little basic exhaust work to connect the older manifold/downpipe to the cat. Cali emissions ones and 01s are annoying from my impression though.

Still I'd take a clean straight 00/01 before I'd get a rotten 99/98.

The LP d30 is annoying but it's a $130 problem at the junkyard, maximum, at least around here. Buy HP d30, bolt in (I've done em in as little as 2-3 hours with assistance and practice) and forget it ever happened.

^ This is what I'm saying.

For whatever reason people seem to enjoy talking about the 00-01's like they're garbage. They're not. Especially if you don't mind putting the least amount of work into them, like Kastein said. Swap out the head and the front axle (if it really bothers you that much) and you've got the best "production" XJ ever made. Don't forget about the upgraded ignition too. Less maintenance/moving parts, and a hotter spark.

And I know this isn't scientific evidence, but just to fortify my point, I put well over 200k miles on my 2000 and never cracked the head. I overheated the crap out of it a couple of times too. It eventually "died" (if you would even call it that) of a cracked piston skirt.

 

[NW-ZJ-SCOTT]

Parents have a 00' with 240k Runs great (Heavily abused and rarely maintained, might I add)

 

[kastein]

I've seen or heard of a few cracked piston skirts on 00+. Rumor has it that it's due to the machinery on the engine production line getting sloppy after that many years of use but I'm not sure how much stock I put in that idea.

Also if you are going to lift and put big tires and different gears in, the low pinion becomes no real waste of time to swap, just pull a high pinion axle at the junkyard, buy the new parts for it, build it, then you can swap it in whole... and pull the low pinion axle to sell to someone on craigslist who just wants a replacement stock axle for their daily driver and doesn't even think about lifts or tires or anything.

 

[N8N_99xj]

2001 here with 172k. I have had to replace all 3 cats and 4 O2's. Not fun or cheap!!

That said, I have blown a rad hose and overheated the engine, I currently have the heat soak induced misfire (I think due to the extra cats. Currently wiring in an Elk-960 timer...). No head crack yet though! I've been impressed. Will be doing the head swap after I am done with some suspension/drivability work.

If I had to do it again I would definitely go pre-2000. Search search search!! Good luck.

What's the timer for? To allow the fan to after-run with the key off? Would like to know more about this; I've seen water temps at 230-235 after shutting down e.g. for gas or stop at convenience store and then restarting, have thought about doing something like this myself, just never bothered to investigate the wiring diagram to see how hard it would be to let the fan run with the key off.

 

[Rockhound-NC]

Re: Re: rule out 2000+ when buying?

What's the timer for? To allow the fan to after-run with the key off? Would like to know more about this; I've seen water temps at 230-235 after shutting down e.g. for gas or stop at convenience store and then restarting, have thought about doing something like this myself, just never bothered to investigate the wiring diagram to see how hard it would be to let the fan run with the key off.

Yeah man its a variable timer so you can adjust how long it operates. Most folks seem to have good luck in the 2-3 minute range. When I kill the Jeep, it flips the efan on for 2.5 minutes. I will link the thread I used below. Only additional thing I plan to change about my setup is adding an interior switch to turn off the timer for the winter. Turn it back on and let it operate from spring - fall when the heat soak is an issue. Good luck PM if you need I will try to help you out.

http://www.naxja.org/forum/showthread.php?t=1028190

How can I hook up an efan timer on a 2001?

 

[20jeep00]

Just replaced a cracked head on my buddies 99 xj, so they can crack as well. My 00 has 132k on it and no problems.

 

[MoFo]

You just nailed the third problem with the 2000 / 2001 XJ. Back in 2010, I tore my 2000 engine apart for a rebuild. I had to drive it 900 miles home from South Carolina after the head cracked while visiting friends. So by the time I got it home, the bearings were too far gone. I had a bad piston slap that I lived with for 18 months. During the disassembly inspection, I found three of the piston skirts were badly cracked, one crack clear into the oil ring groove. I agree that this is a common problem in these years. As soon as you see antifreeze disappearing with no puddle under the XJ, find a TUPY hear, or order a Clearwater head, before you have to replace the bearings. I should have replaced the camshaft too, since it had worn an average of .025 across the lobes, but didn't since the cheapest OEM cam I could find was $250.

And I know this isn't scientific evidence, but just to fortify my point, I put well over 200k miles on my 2000 and never cracked the head. I overheated the crap out of it a couple of times too. It eventually "died" (if you would even call it that) of a cracked piston skirt.

I come from the other camp over the cracked head. I firmly believe it is not IF the head will crack, but WHEN the head will crack. I also don't beleive you have to overheat the engine to make the head crack. I bought mine used in 2002, and it was never overheaded while I owned it.

 

[kastein]

sheepjeep on here had his crack on his current XJ and it's been in the family since new IIRC. Never overheated AFAIK.

edit: and Dundy on here had the piston skirt issue driving down to NACFest '11 as I recall. Ended up leaving the jeep in a parking lot and going down with a uhaul to pick it up later.

 

[kgmkgm]

99 and loving it :scottm:

Unfortunately have the D35 rear, but I have a HP 30 in the front, so I'll take what I can get!

 

[winterbeater]

So many have tried to blame the users for the cracked heads. I don't buy it.

Don't rule out any year, but look at price and features of each. The head can be fixed by yourself for a couple hundred dollars.

 

[holysirsalad]

My take on the 0331 heads is that it really comes down to prior maintenance. The weak casting simply makes it easier to crack, not a guarantee or anything. Keep it in check and you'll be trouble free. The problem here 12 years after the last XJ rolled off the assembly line is that most of them are used vehicles with unknown history. Many have lived lives with poor maintenance and as cheap winter beaters. It's no surprise the issue is so prevalent. It's not a matter of mileage or age, but how many times it's been heated and cooled to the extremes. Keep it even and you'll be fine.

I've seen or heard of a few cracked piston skirts on 00+. Rumor has it that it's due to the machinery on the engine production line getting sloppy after that many years of use but I'm not sure how much stock I put in that idea.

Seems like a load of crap to me. Last I heard about that was 93-94 with odd-sized bores. IIRC Chrysler discovered, with the help of a class-action suit about piston slap, that one of the machines was out of spec. Remember 4.0Ls were produced until 2006 with the same machinery for TJs. I'll reconsider the notion if it was about 2006 4.0Ls and sloppy machinery!

 

[kastein]

Yeah, I'm not sure how much I believe it, but I also don't know anything about failure modes of 02-06 TJ/WJ 4.0s, aside from that many of them suffer the same cylinder head failure (except the later TUPY castings) and 04/05/some range of years in that general timeframe had an issue with the oil pump+DIS drive gear grenading.

Also, the TJ and WJ 4.0 blocks are different externally, all the mounting bosses are different, I don't know if the internal machining was done on the same production line or not.

 

[birchlakeXJ]

Good cooling system maintenance is always recommended, but does not guarantee you that your 00-01 0331 head won't crack.

I've seen a few of them that cracked that have had pristine maintenance. There are many that have kept up their cooling systems, have never experienced an overheat, but still are unlucky enough to have their head crack. Search will get you their threads and stories.

An overheat almost guarantees a cracked head, but for the others....flip a coin.

 

[Fred85]

I haven't seen this emphasized yet, but you should look for something WITHOUT RUST, regardless of year. The differences between late-model years come down to mostly parts, which are cheap enough at this point that it shouldn't influence your decision. The comments about the LP30 axle are stupid unless you plan on wheeling frequently and lifting the jeep...the majority of XJ owners don't.

Regardless of year, you should replace the radiator with an aftermarket all-metal unit. I would advise installing rear disc brakes too, just because the factory drum brakes are that terrible.

I've put 160k on my 2001 so far and the only time it has left me "stranded" is when the AC compressor bearing ate it. I am diligent with maintenance, but this is important with any car. I just had to replace my factory water pump last week, and my stock PS pump is just now needing to be replaced.

I for one like the distributor-less ignition system...1 part replaces 10+. At the end of the day, the '00/'01 models will likely be your best bet for low mileage and no rust.

 

[DrMoab]

You uh...realize that 90% of naxja members modify their XJs right?

I don't think the LP30 argument is stupid at all.

 

[Fred85]

I'm not arguing with that at all...I'm part of the 90%

Let me elaborate (my opinion, of course), if your jeep is your DD I don't think ruling out a good low-mileage, rust-free '00/'01 is warranted just by a LP30...

 

[Jeepguy03]

When looking for an XJ, I looked for one with the lowest amount of rust possible being in the North East. 99-01 seemed to be the least rusty, and '99s were hard to find.

Engines and axles can be swapped, the body not so much.

 

[91AzXJ]

My 2000 has 175K and is running great with the original parts.