Just bought a 2000 XJ 77k miles - Cracked Head

I just picked up a 2000 Cherokee in great condition with only 77,000 miles on the clock! It's black, my color, and in excellent condition. It has a cracked head, imagine that, and I found a ton of water in the oil. Here's my question.......is the engine worth rebuilding (new bearings?) or will the water damage be too severe that it will need replaced. I've never dealt with an engine before that had water in the oil so I don't know what I'm in for. Looking for opinions here........Thanks guys (and gals ;-) )

Pull it apart and see how bad it is - worst case, you were gonna have to get a new engine anyways right? I don't know much about engine rebuilds either, but I figure you can probably see if the damage is REALLY severe, like if the bearing races on the crankshaft are rusted and the pistons are seized or something.

kastein said:

Pull it apart and see how bad it is - worst case, you were gonna have to get a new engine anyways right? I don't know much about engine rebuilds either, but I figure you can probably see if the damage is REALLY severe, like if the bearing races on the crankshaft are rusted and the pistons are seized or something.

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Yes, had planned on doing this anyway. I have rebuilt engines before, just none that have had water damage. I was going to replace the bearings but didn't know if there might be some hidden gotchas to a water damaged engine that someone might be able to share. You know like, "Well with water damage you really need to check blah blah blah"........that's the kinda insight I'm looking for. Thanks for the input.....

92xjdean said:

Yes, had planned on doing this anyway. I have rebuilt engines before, just none that have had water damage. I was going to replace the bearings but didn't know if there might be some hidden gotchas to a water damaged engine that someone might be able to share. You know like, "Well with water damage you really need to check blah blah blah"........that's the kinda insight I'm looking for. Thanks for the input.....

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You don't know for how long the engine was run after the head and/or gasket went.

If it was mine, I would go ghetto. Drain the crankcase, replace the oil filter, put in some cheap oil and seafoam, MMO, or a quart of ATF, and with the plugs removed crank it over to circulate the oil mixture throughout the engine. Then replace the head and fire it up, let it come up to normal temperature then shut it down and drain the crankcase, change the filter, fill it up with cheap oil and run it some more. Once you think all of the crap is clear of the engine put some decent oil in it and drive it for a couple hundred thousand miles--if it doesn't work you can then rebuild the engine.

joe_peters said:

You don't know for how long the engine was run after the head and/or gasket went.

If it was mine, I would go ghetto. Drain the crankcase, replace the oil filter, put in some cheap oil and seafoam, MMO, or a quart of ATF, and with the plugs removed crank it over to circulate the oil mixture throughout the engine. Then replace the head and fire it up, let it come up to normal temperature then shut it down and drain the crankcase, change the filter, fill it up with cheap oil and run it some more. Once you think all of the crap is clear of the engine put some decent oil in it and drive it for a couple hundred thousand miles--if it doesn't work you can then rebuild the engine.

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The guy I got it from said it happened all of a sudden and he drove it 2-3 miles home (limping it along) and then it quit running at his driveway. It has sat for a month before he decided to sell.

92xjdean said:

The guy I got it from said it happened all of a sudden and he drove it 2-3 miles home (limping it along) and then it quit running at his driveway. It has sat for a month before he decided to sell.

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Then I would go ghetto.

I replaced the head on the 01 I'm working on. I bought a new improved casting from odessa for $375 shipped: .http://cgi.ebay.com/ebaymotors/NEW-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Get the Victor Reinz HS 5713A head gasket set as well:
http://cgi.ebay.com/ebaymotors/AMC-...r_Truck_Parts_Accessories?hash=item3ca86ba333

I would drain the oil and refill once you get the head back on and then figure out if the bearings need to replaced. If you still have compression issues after you replace the head, then the rings could be toast as well(I've done that before).
edit: be sure to post up pics of the head so we can see where the cracks are and what other casting numbers are on it(we're trying to document the 0331 cracks). Good luck

You may be able to pick up an earlier HO head on craigslist. I got a good one for $50. Search 0331 head and study up on the numerous threads. Newer used heads seem to be available now too for a little more.

X2 on joes suggestion to replace the head and try it out. If it hasn't been run too long like that you have a good chance of success.

Remington auto salvage has a 99' 4.0 with 70k on it for 600 dollars. It comes with a 6 month warranty. I was just up at their facilities today after buying a 5.3 LS based engine for my miata and was going to buy the 4.0 if mine was found to be bad (thankfully the freezing didn't crack the block or heater core, only the radiator)

Just remember that if you use an earlier model head, you'll have to use a different exhaust manifold(the 0331 has smaller exhaust ports), fab up a coil rail mount(erector set style straps, eg), and possibly plugging the rear coolant port(leave old sensor in).

Some '99s apparently had the 0331 head. Look for the part number cast into the head on the top drivers side halfway back. I think the change was simultaneous with the coil rail. (Long coil box sits on spark plugs.) DON'T get another 0331 head. (unless it was made after 2001, which of course would be non-XJ)

92xjdean said:

The guy I got it from said it happened all of a sudden and he drove it 2-3 miles home (limping it along) and then it quit running at his driveway. It has sat for a month before he decided to sell.

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When it 'quit' running, did it seize up solid, or just run crappy and stall? Two to three miles isn't too much, unless it was leaking for some time, and he finally noticed it. Does it turn over at all? Possibly rod and main bearing replacement. Almost any rust-free body is worth a new engine, and if you got it cheap enough, maybe even a new rebuilt shortblock, or build something fancy.

Was it water in the oil or coolant in the oil?

If it was really just a quick 'event' then Joe Peters way sounds best. If its a wipeout be not much invested OR if its good be a fast way back up. First start up should tell the tale.

Good Luck,
Orange

If you're going to rebuild it yourself, do a stroker.

Hey guys, thanks for all the responses. Yes, this one is definitely worth fixing with only 77k miles. The body is perfect, it has a factory 6 disk cd changer and a sunroof! There is coolant in the oil, very "milkshakish" looking. The guy I got it from said the jeep ran before he parked it and that it was not locked up. He said it sounded bad though.........he is not too familiar with Jeeps. I asked him if he had checked the oil and he said no. I pulled the dipstick and the oil cap and both were white and foamy.

I have 2 4.0's in my garage and I checked them today and they both have the 0630 head on them. I think I am going to pull the head on the jeep I am fixing and see how things look. If it isn't too bad and the engine turns pretty freely I think I will go ahead and slap one of the 0630 heads on it along with a matching header (I have 5 of them) and then do like earlier suggestions, crank it will some good oil and tranny fluid to free it up and go from there.........I like the suggestions about fabbing up the coil bracket and the exhaust comments, much help, thanks. So from what I know I just need to have an exhaust shop complete the link from my pre-2000 header to the pipe in front of the cat, correct?

chpmnsws6 said:

Remington auto salvage has a 99' 4.0 with 70k on it for 600 dollars. It comes with a 6 month warranty. I was just up at their facilities today after buying a 5.3 LS based engine for my miata and was going to buy the 4.0 if mine was found to be bad (thankfully the freezing didn't crack the block or heater core, only the radiator)

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We have some good salvage yards close with comparable prices....most though, charge $150 core charge!!!!!! Do you know if this place does and how far from St. Louis?????

The pre-2000 headers may not have the fittings for the proper O2 sensors, and they won't have the pre-cats, and may end up confusing the ECU. Our latest XJs are '96s though, so I'm not totally familiar with exactly what you'll have to do.
As far as the engine not being seized, that's good news. Swap the head, flush the crankcase, watch the oil pressure, and hope for no clanky noises!

Don't know how your 2000 is setup, but the 2001 I'm working on now has an o2 sensor on each manifold but no downstream o2s. If you don't want to weld a 2nd bung on the earlier manifold, you might be able to tap the signal on the first one to feed the 2nd one.

Don't bother with any used head older than 2002 for a straight-up swap.

Going to the earlier head (0630 or 7120) will require the use of an adapter plate to close off the exhaust ports - and you'll get a reversion issue (from the large "step" at the port exit to the manifold.)

The casting was revised sometime in late 2001 or so, which is why the 2002-2007 heads will work neatly for you. The 242ci continued production until the end of the 2007 model year, and was found in the WJ, WK, and TJ through that time (so they're still out there.)

I have no idea how to identify a "revised" casting elsewise, so avoid the 1999-2001 0331 heads and save yourself the trouble...

Fed 2000 has one sensor before the single cat and one sensor after. CA setup has 2 before the precats and 2 after the precats.

I'm planning the same change from a 0331 to a 0630. Use a pre-2000 header and let an exhaust shop fab up your connection. Another possibility is using a downpipe from a pre-2000.

You have two older ones sitting around, so maybe you can check out another possibility. Use the whole exhaust system from a pre-2000. I'm not sure if the hanger locations are the same. It just seems like the factory systems last so much longer than the aftermarket ones.