Kalali

The only way a new head could cause problems is if its defective, improperly installed or you break something else along the way when installing the new head.

catfish51

I have only owned Jeeps for a couple of years so I'm not really in the expert range as far as Jeep engines go but motors are motors no matter what brand.I have worked on raced and rebuilt Chevy engines since I was 15 years old and I just passed 60 now.
Rebuilt heads on high mileage motors can cause blow by and failure of crank and rod bearings .It's simple when you install a rebuilt or new head on a old motor you increase the compression of the motor because of many factors like good sealing valves and the fact that the head has been planned down .This added compression on a worn motor puts more stain on the bearings and they possibly go or it causes leakage around the piston rings causing blow by.
I've taken chances on putting rebuilt heads on Chevy engines with 140K on them and I have had good results and then again I have put heads on engines with 100k and had them start knocking in 2000 miles.I have had better luck putting used untouched heads on worn motors where I try and get a used head with similar mileage.Hey we all do things differently and sometimes they turn out well sometimes they don't.
CATFISH

Kalali

You're probably technically correct but a lot of folks here including me have replaced the cylinder head at high mileage - mine was done at 175K miles, and the engine lived to see 250K+ miles. The compression did go up in mine to about 170psi using a new head but the low revving engines in the XJ should be able to handle the extra boost.

bryweb

I am no pro either, but I think things like bearings going out on motors with new heads have more to do more with overheating of the motor when the old head went bad or antifreeze contaminating the oil and eating the bearing material, than higher compression with the new head. I myself after replacing a head on an 01 Grand Cherokee afterward had bad oil pressure when it warmed up.... ended up being the Cam Bearings.... which I can't see being caused by higher compression. I kind of look at motors like original paint, once heavily messed with it will never be the same unless a complete high dollar professional job is done to redo it from scratch. Usually with me its either a complete rebuild or throw a junk yard/used motor in it.... usually the second when it comes to Jeeps as I don't want to cry over my high dollar paint or motor when wheeling it.

DallasXJ

I found a mint condition 2000 that I would like to take a look at with 109K, but the cracked head issue and LP are issues for me.

bryweb

I have purchased a number of these 2000-01 0331 cracked head Cherokees and fixed them. (I usually will pay about $1000 with a bad motor, maybe a few hundred more if it has add-ons I want like lift kit) - keep in mind with a car you can not drive there is a bit of risk, is the trans good, did the ethanol in the gas go gunky, does it have the death wobble, etc. - I usually beat the seller up with these questions to get a good deal.... explaining the risk I am taking (which thankfully rarely bites me in the butt)

The Dana 30LP vs. HP is not a big deal, usually you can find a Dana 30HP for $100 - $150 and its an easy swap. (and you end up with a spare set of axle shafts and hubs)

As far as the motor, I prefer 96-99 motors swapped in (but 91-99 will fit), these I find all the time for $250-350 at PicknPull, Craiglist, or Facebook groups (You need just the long block which includes the head) mount the 00-01 intake & accessories to it and order an eBay "2000 Jeep 4.0 Stainless Header" for $140 (needed to cover the bigger exhaust ports on older heads)- So for about $400-500 and another $100 in fluids, gaskets, etc, and a couple of weekends in the garage you got yourself a great jeep.

If you do the swap, let me know I can help get you in the right direction in regards to setting up the cam sensor, using the right Permatex silicone on the intake/exhaust gasket, making simple brackets for the coil - or just search my posts and you will find the answers.

http://www.ebay.com/itm/00-06-Jeep-Wrangler-4-0-I6-TJ-Stainless-Exhaust-Manifold-Header-01-02-03-04-05-/251998188188?fits=Year%3A2000%7CMake%3AJeep&hash=item3aac43329c&vxp=mtr

SantosClaus

Not to Hijack either, but I had a TCC issue for the longest and the radiator I inherited was terrible. I replaced the RAD/TempStat and Housing/Clutch Fan/ Water pump 8mo ago...I changed the Tranny solenoids and filter and filled fluids this past weekend. I drove the jeep today and it overheated (never did before except when I first got it and Jiffy Lube left air pockets). I stopped let it cool down and drove it again because I was a few miles to the next autozone. This time it never overheated but a lost power and noticed smoke in the rearview, so I pulled over and the cloud began and now it overheats. I get out and notice that there is oil everywhere but not coming from the head gasket area. I try to fill it up with water and I had a spare qt of oil but no start, it still smells burnt hours later...I get towed and eventually get it started so I can trace the source. I now notice a build up of smoke in the valve cover and let it get to core temp and notice a hissing sound and track water dripping rather fast... behind the water pump was a large size leak but looks like it is coming from the block and I never had a leak before. engine sounds horrible now, what could it be? I haven't noticed oil in the RAD and no sign of mixture in the oil...I will remove the oil pan and valve cover tomorrow and inspect, but the oil was changed a few weeks ago, please help!!!

Kyle Mills

So which engine was this dowel pin

Kyle Mills

What engine was this measurement from?

Matthew Price

Sorry to post on this old thread. My local junk yard has a 2003 Grand Cherokee. Is that head plug and play on my 01 Sport, or are there modifications to make it work?

bryweb

2002 to 2004 WJ Grand Cherokee heads are "Bolt In" on your 01 XJ to replace the cracking 0331 head, make sure it has TUPY stamped somewhere on the head, it should being a 2003.

PS: Head bolts are only reusable once, to be safe I would get new head bolts, also you will need thread sealer for one of the front head bolts that go through a water jacket.... then of course you will need the head gasket, and might as well do a valve cover gasket why its off. FELPRO is my preferred gasket choice.

Mark Poynter

So glad i found this thread. I put some money down to hold a 2001 Cherokee 4wd Limited today until I can get it to a mechanic on Monday. Jeep has 88,000 miles and looks very clean. The price is crazy for this Jeep but not sure I will be buying this one. I will drive down and check out the head # and go check out a 1999 with 140,000 miles also tomorrow.

The cherokee seems to fit the bill really well for me. I plan to tow it behind the motorhome as soon as I retire in 11 weeks. Need the 4wd for the desert and mountain traveling.

2001 Limited they want 11,000
1999 sport they want 4,500

Thanks for this post everyone!

Mark - San Diego

Tony the Liger

I would have a VERY hard time justifying an $11k price tag for an '01 XJ. That's absurd.

I know the value's gone up lately, but these are XJs, not FJs.

Mark Poynter

I agree! Ridiculous. With a head issue I am now thinking 3 to 4k if the head isn't cracked.

Noah Wallace

sorry to jump in here but I'm desperate...

I recently had a little hesitation while traveling at about 35mph. I figured it had been awhile since I did my plugs and wires, so I did that. A couple days later after stopping at a light and accelerating again, it was really chugging, not accelerating much. I pulled over and right before it seemed like it was going to stall, it revved up and everything was fine again.

I checked the plugs and didn't like the gap they had (3 electrodes, pre gapped) and two of them had a little black char on them, little enough to just wipe off. Well it kept happening so I replaced the plugs completely, again. Kept happening. Took my cap off and inspected the rotor, tiny bit of corrosion on the tabs but I just brushed it off. Everything worked fine for a few days, now it's doing it again.

now I have no clue, clogged catalytic converter? Fuel filter? The whole engine is filthy so if I had a cracked head or something I can't tell, seems pretty greasy everywhere down there. Valve cover gasket I did a year or two ago. I'm just at a loss here. Any help is appreciated!

oh its a 97 xj