MOTOR HEADS

I just picked up a 2000 xj for a thousand bucks, 127000 on the ticker
I knew it had a motor issue going in, the problem is oil pressure, It has none. Maybe 5psi at idle.20 psi at 2000rpm's the guy changed the sending unit and it has a napa gold oil filter. the oil looks ok as in changed in the last 1000 miles.
He was told that the block is "cracked" Is that a common problem with4.0's? I haven't heard of it, I was thinking damaged oil pick up or faulty oil pump maybe.
If the engine was just worn out I would think it would sound loud at least, but it sounds ok to me. Any insight would be appreciated.:dunno:

I'll give you 500 for it.

Maybe a faulty oil pressure sensor, I know on the earlier models they peg out when bad. Not sure how the newer ones act. I havent heard of a cracked 4.0 block.

check the head. most likely the 0331 casting. Theres a few people on here that had that problem. Most recent was BHICKS, his had a cracked blocked, and he just put a long block in.

xjjeeper19 said:

check the head. most likely the 0331 casting. Theres a few people on here that had that problem. Most recent was BHICKS, his had a cracked blocked, and he just put a long block in.

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Well I just read the thread Bhicks problem matchs mine exactly,anyone know if later model 4.0 2001 and on are a good fit to a 2000XJ ? I,m thinking a junkyard motor from a 2001 or newer might be the answer.

As you already saw my thread, my 0331 head cracked and I drove it that way for over 12,000 miles fixing everything under the hood and finally realizing it was a cracked head. I replaced the oil sending unit, both cps sensors, oil pump, fuel pump, and a lot more. By the time I realized the head was cracked it was too late. The engine was toast. I ended up cracking the cylinder wall in the #1 and #6 cylinder. Too much coolant and friction in the block for too long. My oil pressure was terrible and continually got worse. My coolant turned brown and my oil looked like chocolate milk. The oil cap had this milky brown sludge and my tail pipe would occassionally blow white smoke. Usually when I first started it. Even after all the crap the motor went through it always sounded great and ran strong. All the way up to the day I yanked it out. In regards to the solution, it depends on how much money you want to spend. You can use a 4.0 from a newer TJ but you will have to change the oil filter pickup. The newer 4.0s in wranglers have the filter sticking straight out of the block. The cherokee has a 90degree adapter to allow it to fit between the front frame rails. It is an easy swap. I almost went with a 03+ Junkyard TJ motor but my XJ is my daily driver and something I very much love and plan to drive for a few more years. Doing the junk yard swap wasn't really sounding like a great plan for my needs. I really wanted something with a warranty so I had a little peace of mind. The rebuilt motors went for about $1,100 and had warranties up to a year with 12,000 miles. The reman motors came with 5 year 100,000 mile warranties and were basically all brand new except for the block itself. I ended up going with a reman from nihon motors. Was delivered to my front door within a week, free shipping, and a 5year 100,000 mile warranty. In total it cost me just over $1,500. Not sure if that is a price you can swallow. It really depends on how long you plan on keeping your rig and what you are going to be using it for. If it was just a toy and weekend wheeler then I would have gone cheapest path possible. If you need help with the motor swap, let me know.

Sounds like you got a deal. Here's my take on it, and I'm not sure how good you are at wrenching, but for the price of a re-manufactured 4.0, you could drop in a stroker motor. Check out the jeep stroker list. There's also a few people on here running strokers. Not much more than a stock rebuild, unless you get really blingy with custom pistons and stuff.

markw said:

Sounds like you got a deal. Here's my take on it, and I'm not sure how good you are at wrenching, but for the price of a re-manufactured 4.0, you could drop in a stroker motor. Check out the jeep stroker list. There's also a few people on here running strokers. Not much more than a stock rebuild, unless you get really blingy with custom pistons and stuff.

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I looked into the stroker motor and was fully pursuing that path as my #1 option. The more I researched, the more I didn't like the option. I had numerous guys mention that getting it to pass smog was challenging in Cali. I also couldn't find any company that would give it more than a 3-month warranty and the companies that actually sold them complete stated it wasn't the best engine for a daily driver. The best deal I found on a reman stroker was $2300 and that was simply out of my price range. It was real difficult to swallow that number when there was a huge risk that I wouldn't be able to pass smog and couldn't get that warranty. If cash wasn't a problem and this was simply offroad use only I would for sure have gone with the stroker, but as a daily driver it simply didn't suit my needs. I also have a wife who ONLY cared about the warranty and the only way I could get her to be on board with me dropping $1,500 into a repair on a 9 year old Jeep was to get that 5 year 100,000 mile warranty.

Well I found a motor 4.0 from a 2002 installed for $1400 so I think we are going that route motor has 84k on it so I hope it will last a while.
We were going to rebuild the existing motor but that is a big and time consuming task.
Wish me luck!

lamula said:

Well I found a motor 4.0 from a 2002 installed for $1400 so I think we are going that route motor has 84k on it so I hope it will last a while.
We were going to rebuild the existing motor but that is a big and time consuming task.
Wish me luck!

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You are getting the motor WITH installation for $1,400? That is a pretty good deal. The best deal I could find to have someone install for me was $1,000 and that did not include the motor. That was going to be at least another $500 for a pick a part motor.I figured if I was going to drop $1,500 I might as well go with the reman. Ofcourse I had no idea what I was getting into in regards to the motor swap. For $1,400 go for it. A motor swap was a much bigger job than I had assumed.

Engine swaps aren't that bad if you have a shop with a full set of tools (i.e., lift, tranny jack, engine stands, extra set of hands, etc.). but yeah, doing it in your garage with a socket set and some jackstands definitely adds to the challenge!

SanDiegoXJ said:

Engine swaps aren't that bad if you have a shop with a full set of tools (i.e., lift, tranny jack, engine stands, extra set of hands, etc.). but yeah, doing it in your garage with a socket set and some jackstands definitely adds to the challenge!

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Yeah, it sucks. I know my Jeep better than I ever wanted to and it knows me well to. That engine has my skin and blood all over the damn thing. My knuckles look like hell. Vince (another guy) has a big pool of blood on my garage floor. He busted the back of his hand wide open.

If anyone knows, when did they stop with the 0331 defective heads?
I think some told me one mid 2001, does that sound right?

lamula said:

If anyone knows, when did they stop with the 0331 defective heads?
I think some told me one mid 2001, does that sound right?

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I went over to the TJ guys on Jeepforum.com and asked the same question. It seems that by 02 the problem was pretty much fixed. A couple guys said that there were a few 02 guys on the forum that had the cracked head no nobody with an 03 or newer seemed to have the cracking issue. The 02 is a rather safe bet but the 03+ seems to be a guarantee. When I ordred my head I made sure it was from an 03 or newer. When I got it, the tag on it showed it came from an 06.