When you yank the head off and clean the block, you WILL inevitably get crud into your coolant and oil. It's advisable to change the oil within 300-500 miles of pull the head. Some folks do it as soon as they bring the engine to operating temperature. In fact, I would change the oil twice that way before going back to normal oil changes. You may need to change the coolant twice as well. Use 50/50 Zerex Original Green Antifreeze or equivalent + Distilled water available at any grocery store or Wal Mart. I buy the Zerex at the local farm and ranch store for less than $10 a gallon. Fresh coolant is nearly translucent, i.e. if you shine a light in the coolant jug you should see the bottom of it. Be sure to have a torque wrench for torquing the head bolts and follow proper sequence which is basically start in the middle and work your way each side evenly. If your lifters are especially noisy now is the time to change them because you have to pull the head to do it. The manifold bolts can be a real bear to get to the first time you do this. I find it easiest with a universal or wobble extension. Some people use ratcheting wrenches. Keep in mind that every nut and bolt that goes directly into the block or head is standard thread (not metric) but some sizes are so close it is not that important. Valve cover bolts and studs have 7/16" head but 11mm works. Thermostat and water pump bolts have 1/2" heads but 13 mm works. The rear driver's side head bolt cannot be removed with the head still in the Jeep so don't even try. And you need to put the new one in the head and tape it up when you put it back in. The front driver's side head bolt goes through a water passage so you should Loctite 592 or plumber's putty on it to seal it. This head bolt also has a final torque lower than the others. I assume you'll get into some details of it, these are just some common sense tips and pitfalls.

 

Agreed but...plumbers putty? That's a new one. Myself I'd use the recommended. (plumbers putty is not used on threads, even plumbing!) We sometimes use Rectum Seal, instead of Teflon tape. (Putty is for filling spaces, like below the ring at the tub or sink drain).

It's OK to reuse head bolts once. In a perfect world you would mark them with paint so the next guy knows they are on their second, (last) run. At 130K it's very unlikely your 0331 has been changed before. (if they have paint marks, then spend the what, $50 on new)

Not to dis MD, good solid info in my opinion!

 

Toss a new head on there, and wait for it to 'splode! I'd also change the oil constantly or stop driving it. You're doing damage constantly.

 

a lot of people have been saying try to remove the head and the exhaust manifold intake at the same time. can you also go about putting them on the head before you install it? and how would I do this and torque it down without damaging the head and what's more how would I go about putting it back in the engine any advice on that would be appreciated because I think I would much rather do than not being able to reach anything underside and risking a minifold leak..can it be done? and how? Does anyone know of a write up on this, I've searched but can't seem to find much information.. additionally can anyone point me in the direction of what I should look for once my heads off and if I should replace anything I know that I should check my rocker arms to see if they move and my push rods to make sure they're straight, anything else that I can benefit from cleaning while I'm there are replacing would be appreciated too just trying to do my homework before I get started so I don't make any mistakes and miss something that I'll wish I could have done.

 

I pulled everything out piece by piece and wasn't hard. I wouldn't want to try to lay the head on a fresh gasket with the manifold attached and risk damaging the gasket. The head is something around 80 lbs so get another guy to help. And the manifolds aren't that hard to tighten but I couldn't get a torque wrench in there. Ratcheting wrenches.

 

I do not have an engine hoist and remove the manifolds then remove the head. Many of the folks who seem to remove the manifolds and head together have older Jeeps without the pre-cats. Consider changing the lifters since the head has to come off to do that. Since you need to drain the coolant, you might consider cooling system work such as replacing the metal tube off the water pump if it is rusty, the hoses, fan clutch or water pump. The grommets on the valve cover often turn to stone and are cheap and easy to replace. The breather tubes to the air box and manifold also come to mind. Fan belt.

 

I have fixed muffler and indeed do hear a slight knock but the rattle up hills is gone lol. I did change oil because I had to drive it. went with 10 30 instead of 10 40 which is what I was running and oil is actually just under spec, so after much consideration I guess I am gonna save and save and just get a remaned long block put in. Seems like the most reasonable option seeing as I plan on keeping it for a long time. Thanks for all the advice again, will update when the time comes to let everyone know how it goes.

 

Absolutely do not use a 0331 head, remanned or not. They can't get around the factory casting flaw.

You're only going to recondition the short block, and buy a new aftermarket head.

 

This 90 Has been doing this since I bought it in 02 @ 135K. (partly why it was only $2K)..... 282K now, and running fine and strong. My latest thought is it might be crank end play, Idk! Numerous posters hearing that, HAVE POSTED THAT theirs sounds the same. My "new" 90 with only 200k, I wouldn't hear it....... except I know. This hard to explain. Like a smell you might recognize because you smelled it stronger before. The "clack" is there in the newer, but so subtle it would be pointless to try to record.

A potentially pertinent question might be, does your knock sound like this, or is it different.

 

I have been looking around at a few vendors and one specifically stated the 0331 is a beefed up version that comes with it. Dont worry I will make sure its not the original casting. What exactly do u mean by " your only going to buy a reconditioned short block"
Is that a question or suggestion? Either way I figured long block would be the best way to go that way I can just bolt in and go I don't have the knowledge to rebuild myself.

 

Yeah, and how exactly is it "beefed up"? Are they willing to guarantee, parts and labor forever, that it will not crack? In writing?

Only the TUPY 0331 heads are worth having. They were used on 4.0s around the 03-04 era.

A short block is the reciprocating assembly only. A long block includes the head. You will be rebuilding the short block only. You will replace the head with a new, not rebuilt head. Unless you choose to go with the TUPY 0331. They can be reused and rebuilt.

Who you have mate them together is up to you.

 

So...I just did this swap at the beginning of this month. I scoured the internet looking for write ups, tech guides, parts, etc. I found a ton of stuff and I want to pay that forward. So I've outlined your questions a little bit..here we go.

1. This is definitely the way that I recommend doing it. It was VERY easy to pull the intake, exhaust manifolds, and head out all at one time. Just have to make sure that everything is unbolted and the bolts that go into the exhaust downpipe are unbolted. These can be a pain though, soak them and use an impact.

2. Yes. Before I installed the head back onto my motor, I put my intake and exhaust manifolds back onto the head. This made torquing them down way easier, and also gave me extra stuff to hold on to when I was putting the head in.

3. I had pieces of cardboard on the ground and just tilted the head up on its side. Laid the gasket down on top and lined it up, and then very carefully lined up each exhaust manifold and then the intake manifold. It was like a perfect balancing act making sure they didnt move when I was reaching for the first few bolts. I had to stop and reset it 3 or 4 times, and then once my bolts were on a few threads I had to readjust the gasket as I went down on the bolts. Take your time though, you do NOT want an exhaust leak from a part that you just fixed. Mine had no leaks when reinstalled.

4. I enlisted the help of my dad and brother. I sat on the top back of the jeep (like where the bottom of the windshield is at) and took the back of the head. Brother took the front, we lifted it up and down onto the block while my dad lined us up onto the gasket and help us get it seated. After we got it on, we realized we forgot to look at the UP thing on the head gasket. So we lifted the head back off, checked, and put it back on. All of this only took us about 5 minutes all said and done.

5. It can be done a lot easier than you're thinking it will be

6. There's a lot of information out there, just have to look on a few different websites, youtube videos, haynes, and the factory service manual if you can get one.

To get you started, here's a pic of everything that I bought and replaced when I did my head. I went a little overboard, but I'm a perfectionist.



I took my time doing research and spent about 3 weeks sourcing parts from different places. Not pictured: Copper RTV sealant, Brake cleaner. Buy a couple cans of it to clean miscellaneous pieces and parts. You're taking them off, you might as well clean it, right? Starting at the top left, working my way right we have
1. 5 gallon buckets. Get 3. ($6)
2. Loctite #592. This is for bolt number 11 going into the water jacket on the head. It's a thread sealant, NOT normal loctite. ($10)
3. New electric fan ($54) Mine was broken and help in with zip ties
4. New fan shroud ($30?) Also broken and zip tied
5. Lucas bottle of assembly lube ($8) which is sitting on top of
6. New lifters ($120). There's a lot of fight on this topic. Just buy them and replace them. You're already in there, it made my engine purr afterwards.
7. (at least) 6 quarts of oil. I have more in big gallons not pictured. ($40)
8. Mopar oil filter ($6), or wix, your choice
9. Green coolant (~$30)
10. Aero-Kroil. I cannot tell you people how amazing this product is. It's expensive, but you need to buy it. It eats away rust like pb blaster's older steroid ridden cousin who just took a bunch of meth. Those 2 cans set me back $50 with shipping. However, once I soaked the manifold bolts overnight, I was able to break them loose with an 8 inch ratchet wrench. A ratchet wrench. These are bolts that my 26" breaker bar couldn't break the previous day.
11. Fel-pro gasket set. This had a head gasket, valve cover gasket, some other odds and ends. ($150)
12. Fel pro head bolts. Just buy new ones. These set me back $30 for the set from o-reilly auto
13. (working right to left now) New water pump + gasket. GET IT FROM THE DEALER ($60). Do not cheap out on an autozone pump. Your dirty *** oil went through this thing thanks to the head being cracked. Replace it and don't worry about it. edit: The gasket I used was a fel pro one. The one that comes in the box is a stupid paper one.
14. CCV valves ($10 total. Bought as a precaution in case I broke mine. I ended up not needing these)
15. New serpentine belt and a tensioner because I didn't have one. My belt was on the way out. Up to you whether or not to replace it ($40)
16. Thermostat and thermostat housing. Use a 195* thermostat.
17. Grommets for CCV valves
18. The little sword looking doohickey is a hydraulic lifter puller. ($12)
19. New hoses. Included here are upper and lower radiator hoses and heater hoses from the water pump and the thermostat housing and an extra one. Dont remember how I ended up with it but I had one that didn't fit anywhere so I left it off. ($don't remember)
20. CCV seal/tubing
21. Water pump solid threaded hose ($ don't remember)
22. Square box has a new idler pulley in it. Old one was squeaky
23. The cylinder head. New 0331 casting from clearwater cylinder head. Had to send yours back as a core so don't rip open the box like a banshee because you're excited for jeep parts.
24. Purple towel. It's mine, you can't have it. ($priceless)

So like I said. I overkilled it a little bit but since I had half of the engine taken apart, I wanted to replace everything that I put my hands on. And let me tell you, it was worth the $1,000 I spent on it. My jeep purrs like a baby kitten and decided it doesn't need to show me the check engine light anymore. I need to head off for the moment, but I can PM you a quick walkthrough tomorrow, or at least send you some of the guides I used if I can find them.

 

Great post kee, people will benefit from that!

howellroby, I edited post $24. You might take another look. Yes. posters who suggest replacing anything or everything must have a stellar record of nailing the problem.

The most economical solution can indeed be tricky. The 4.0 is a tough old Goat..300K is not rare. People go 10's of thousands of miles with nearly no oil pressure at hot idle. A good head just might make your day!

 

Prestone and other universal coolants are garbage. Get some conventional green.

 

Do you have any hard scientific data to back up your statement?

BTW, Prestone is green.