potential 0331 crack
 

Got my 2000 cherokee about 6 weeks ago. 4.0 164,000 mi. Last week replaced intake manifold (cracked). That took care of rough idol and CE light (misfire). Today noticed coolant res was about empty (was full last week). Oil fill cap had very minor white cream. I think I can see air bubbles in a line under fill cap just after I shut it off. My mechanic friend says I am paranoid and told me to keep an eye on it. I just don't need to trash my bearings. Its my DD for work (100 miles a day). How long should I "keep an eye on it" for? Dipstick had no signs of coolant contamination. Oil pressure 50 psi @ 2500, 20 psi @ idol. Seems to run good. I appreciate your opinion. Thanks for reading.

$25
http://www.blackstone-labs.com/

If you have white frothy stuff under your oil cap... Obviously you have a coolant leak somewhere, be it the head gasket or... 99% chance that your head is cracked.

I just did a head swap on mine. If you HAVE to continue driving it, you are going to want to change your oil EXTREMELY frequently to avoid bearing damage. The best course of action is to park it and find the problem.

Remove your valve cover(5 minutes), and squeeze the largest coolant hose. Observe the space in between the third and fourth cylinder while squeezing (90% of the cracked heads crack here. but also observe the rest of the head for cracks as well). If the crack is bad enough just squeezing this hose will disperse water through the crack and you can pinpoint it.

If squeezing doesnt work... do the same thing but instead of squeezing the hose... remove oneof the smaller hoses and pressurize with a small compressor to roughly 16-20 PSI. This should definitely push water through a crack in the head.

Also you could always let the vehicle idle with the valve cover off but this can get messy as oil will sometimes shoot out of the push rods. Lol.

Report back and let us know what you find.

If you do the head swap I highly recommend changing your lifters as well. The combination of water and oil will devastate them and you will most likely have stuck/munched lifters because of it. No need to take the head off twice because you get the job all done and now your truck sounds like a damn diesel...

Well I did as you said. I put a little pressure in the cooling system thru my heater hose with a hand pump while it was cold. It took a little while, but eventually little green droplets formed on what I thought was the crack. Between the #3 and #4 cly right along the #4 exhaust valve guild. I also got it up to operating temp, shut it off and squeezed the upper radiator hose and saw tiny air bubbles. While it was getting hot I noticed I had a large puddle on my garage floor from the tail pipe. I know a little condensation is normal, but this was definitely excessive. It even fogged up the windows of my garage door! So now that I confirmed that my head is cracked, what is the opinion about clearwater heads? I don't have time to hunt down and refurbish a tupy (I've already tried to locate one, just in case, with no luck).I need a head soon. Suggestions?

Where did you buy it from, it probably needs a motor. Engine oil + ethylene glycol creates acids as well as abrasive "oil balls" that eat through bearings in short order. There is no "extra" bearing material to begin with. Myself, I would either be looking for a refund, or slap a head on it and dump it. Personally I have to be at work M-F and can't afford to screw around with a vehicle that isn't as close to 100% reliable as I can get it.

I got it "AS-IS" off a lot. Probably got took. No refunds here. Unfortunately I've got too much into it to just dump it (new brakes, u-joints, intake, etc.). The rest of the jeep is in great shape. If I put a new head on it should I plan on rod and main bearings also? Id like to get at least 100,000 miles out of it.

I have no idea where you live or where you bought the Jeep from. But I would look into the lemon law where you live. I know that many states not all have passed the lemon law for reasons like you have. Even if it is sold as is, new or used they do have to honor it. That is if your state has passed t into a law. Hopefully you are in one of the states that has passed it. Other wise you got screwed and more then likely they know it had a problem. I would stop driving it and have the head changed out before you have to do a complete rebuild.
Good Luck and let us know what happens.

I'm curious. Could you have seen the crack through the oil filler hole?

AND. You still might talk to the manager at that dealership. Can't hurt. Tiny chance he want's to be honest. Maybe there are even State laws?

Guess you don't know if it was run with much worse oil in it. Just doing the rods is relatively easy, and cheap.

I live in Michigan. As I understand it, lemon laws only apply to new vehicles here. I got it off a small lot, not a big dealership. My guess is the guy won't care. I can see the crack thru the filler hole. I didn't even have to pull the valve cover. I didn't know about the 0331 head problem until about a month after a bought it. I heard about it thru this forum. If I would have known......but anyways I think I got screwed and I'm man enough to say it. I just want to fix it and get on with life. My mechanic friend recommends an older head and fab coil mounts. I would prefer a new casting or re-manufactured tupy for ease of installation. Just looking for opinions. I know alot of you guys have been thru this already. I think this forum is great and you all have good advice. Thanks for your help.

x2 very professional company and easy to work with

Don't panic... invest in a head from Clearwater or J&C enterprises. I got one from J&C, great casting.

I would swap out the head and headgasket... its not a bad job at all and go to a sythethic oil.. they say Rotella T6 is nice.

If it's not knocking and still have good oil pressure, just run it with the new head... but I would NOT drive it as it is now at all!

That sucks if the lemon law only covers new vehicles in you state. I would still double check it. Maybe there is something that will help you out in it?

It happens to all of us sooner or later.

Is this the same one that told you "My mechanic friend says I am paranoid and told me to keep an eye on it".The best route would to do like you said and find yourself re-manufactured Tupy.

Now that you have a Cherokee this forum will be a lot of help.
Like I said. I would reread everything about the lemon law for Michigan and with a little luck there may be something that may help you. Also what every you end up doing stop running the engine so you don't have anymore problems then you already have. Let us know what you pl,an on doing and if you need any advice there are plenty of us around to help you with what we can.

I ordered a sample kit from Blackstone, but I will probably have the head fixed before it gets here. does J&C have new castings? or are they just reconditioned? Do you know if they deal with tupy heads? I've heard that if it doesn't say tupy on a 0331 don't do it. Rotella you say? why? My Jeep isn't going anywhere like this. I'll be using the wife's minivan for a week or so. My friend knows that I tend to worry too much. He was probably just trying to get me to relax a bit. Once I told him about the coolant seeping from the crack he knew it was bad. I trust him we've been good friends for years.

I replaced the cracked 0331 on my 2000 XJ 6 years ago with a Clearwater reman head. Went with the 0630 (1999 head) and had to replace the exhaust manifold and downpipe to match it all up. Some minor modifying was done with the O2 sensor and the coil rail, but now have 70,000 miles on after the swap and it runs perfectly. I think I had $575.00 in parts to do the job including a new water pump and belt, plus another $15 budgeted for the beer.

Did someone say beer?