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Possible 0331 Cracked Head ?

chris420

chris420

NAXJA Forum User
Location
California
I recently had a 3 core CSF radiator installed in my 2000 XJ. The install was done at the dealer. After 2,000 miles I noticed that the resivore needed to be toped off and the radiator was a little low. I added a quater of a gollon of Prestone 50/50. I then did a 500 mile road trip and when I got back home I noticed the radiator was low and the resivore was empty. I then added the remaining 3/4 of a gallon of Prestone 50/50 to fill everything back up again. I did not notice any leaks and the oil in the sump is clean. I do not have any overheating issues the engine stays 180-210. My question is if the head was cracked would it be possible to burn that much coolant? Or do you think the dealer ship did not fill it up properly?
 
on my 2000 when the head gasket went it was incredibly obvious, if you opened the oil filler on the top of the valve cover. Other than that it ran perfectly fine and you wouldn't have known it had a problem. However i don't think the coincidence of you putting in a radiator somehow cracked your head. Did you have an overheating episode before? Any other reasons why you might think your head is cracked?
I'd check all the other fittings, hoses, waterpump for leaks before i jumped to thinking the head was cracked.
 
I had a 0331 head crack. I didn't realize it for awhile and I was unaware that these heads had problems. There were no signs of a leak other than missing coolant. No milky oil, no external leaks, no exhast smell. I figured maybe the heater core was leaking a little or something stupid. I eventually found out that they crack between the # 3 and 4 cylinders and if you look in the valve cover you can sometimes see the crack running left to right between the vavlve springs. Mine leaked a little, but the engine heat was enough to cook off any internal sign.

I realized how much engine damage I did by not taking care of it when (what seemed like) every rod bearing started knocking spontaneously and and at idle my lifters collapsed and sounded like a bucket of bolts. Every bearing in the engine was wasted. The engine only had 100K on in. :fuse:

Find out ASAP!!!!
 
RANSOM said:
but the engine heat was enough to cook off any internal sign.
Click to expand...

Not entirely true. The engine burned off any visible signs. However, a coolant leak with leave potassium and calcium in the oil that will be picked up by a used oil analysis. That is how I found my engine had a problem on my 2000.
 
RANSOM said:
I had a 0331 head crack. I didn't realize it for awhile and I was unaware that these heads had problems. There were no signs of a leak other than missing coolant. No milky oil, no external leaks, no exhast smell. I figured maybe the heater core was leaking a little or something stupid. I eventually found out that they crack between the # 3 and 4 cylinders and if you look in the valve cover you can sometimes see the crack running left to right between the vavlve springs. Mine leaked a little, but the engine heat was enough to cook off any internal sign.

I realized how much engine damage I did by not taking care of it when (what seemed like) every rod bearing started knocking spontaneously and and at idle my lifters collapsed and sounded like a bucket of bolts. Every bearing in the engine was wasted. The engine only had 100K on in. :fuse:

Find out ASAP!!!!
Click to expand...

This exact same thing happened to a co worker of mine this week. The thing runs great but looses coolant. He had a compression test done and all is well but when they pressurized the coolant system AF would spray out of a small crack between 3 and 4 exhaust valves. He had to buy a new head.
 
I also have the 2000 0331. It's using coolant. Runs perfect. But the bottom of the oil fill cap on the valve cover shows milky every time I check it even though I wipe it off every time. When I look in my other vehicles, there is never any milky stuff, so it convinces me that the head is cracked. 103k miles. I picked up a 0960 head and header to fix it.
 
I had my head gasket replaced at the dealer not to long ago because it blew. I asked the dealer to check the head for cracks but they said everything was fine. How much does it cost to have the oil anylized?
 
I recently had a 0331 crack, it did have milky oil, so i had the head checked and the machinest told me it was fine, reinstalled with new gasket and less than 50 miles later coolant reappered in the oil, so i pulled the valve cover and pressurized the cooling system crack was visible right by the exhaust valve on #4, heading right towards #3. so i got a new Alabama Cylinder Head from 4WD Hardware, no probs since! I guess my point is that I screwed up, i should have just put on a new head since i knew these were prone to cracking, instead i did the job twice!
 
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My engine has 91,000 miles on it. I have replaced every seal including a new oil pan as well as a new water pump. If my head is cracked could it have caused damage to other parts of the engine such as bearings. Should I just buy a new engine insead of replacing the head.
 
If it is in fact leaking as much as you say in your original post, there is a good chance you have internal damage. However, you can pull the oil pan and inspect the bearings and plastigauge them.

You also said you filled it up only twice since the rad change. There is a possibility of the system not being burped 100% after they replaced the rad. Did you have to top it up yet again?
 
The radiator is full. The resivore needs about a 1/4 gallon.
 
I was recently given a 4.0 out of a 99 Grand Cherokee that has a cracked 0331 head on it. The motor has 80k and had been driven for a while with a cracked head.


The main bearings still looked like new, however the rod bearings show some wear. The engine was completely gunked up. I wouldn't worry too much about the bearings and such, just flush your motor out good with some marvel mystery oil or kerosene mixed half and half with motor oil.

Here are some shots of my "free" 4.0 with cracked head.

P1010723.jpg


P1010728.jpg

P1010736.jpg

P1010735.jpg

P1010732.jpg

P1010742.jpg

P1010738.jpg

P1010739.jpg
 
Thanks for the picks. I have not noticed any milky residue on the dipstick or oil filler cap. I also looked inside the valve cover with a flash light and did not notice any coolant or milky residue in there either. About 14,000 miles ago I replaced the oil pan and rear main seal and everything looked fine then. I am going to fill the resivore back up and continue to check it after my daily comute. I would think if it is leaking a lot that the coolant would be in the oil pan.
 
chris420 said:
Thanks for the picks. I have not noticed any milky residue on the dipstick or oil filler cap. I also looked inside the valve cover with a flash light and did not notice any coolant or milky residue in there either. About 14,000 miles ago I replaced the oil pan and rear main seal and everything looked fine then. I am going to fill the resivore back up and continue to check it after my daily comute. I would think if it is leaking a lot that the coolant would be in the oil pan.
Click to expand...

Yep, when I drained the pan on that engine the first gallon that came out was AF!
 
Ok so I have been checking my coolant level every day and have noticed that it is disappearing. So today my resivor was empty and my oil filler cap was milky and I could even see some green coolant on it. I have put about 2000 miles on it sence my last oil change and have lost about 1/2 gallon of coolant. I need some advice.

1. Sould I replace the engine and not just the head? (Not sure how much damadge the engine has sustained but it is making a nocking noise like a valve is messed up).

2. What should I do to get the most out of this engine before I replace it?

3. If I need a new engine what company would be the best for the price?

4. Should I get a Hemi swap?

5. I want the best engine for the price I am on a budget

Below is the picture of my oil cap.

 
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1) You would need to inspect the engine to determine the extant of the damage. I would at least replace the bearings and lifters.
2) You could run it until it has a major failure or just replace the head and run it, but I wouldn't.
3) Get a used engine or find a local machine shop to do a simple rebuild. If you can't find local Jasper makes some good engines. Just break the cam in correctly.
4) If you are on a budget don't even consider any swap other than another 4.0L

Look into Alabama cylinder head for a reinforced 0331 head. If you do get a used engine swap the head out with either the Alabama cylinder head or if you can find one a '03+ head (some people say they fixed the cracking issue in '02, but to be sure I would look for a '03.)
 
How much should I expect to pay for a rebuild? If I buy a crate motor how much should I expect to pay to have it instaled? What do you think about Hesco crate motors?

Sorry for all the ??? just looking for good advice.

Thanks.
 
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