View Poll Results: How many miles on your 4.0 when cylinder head cracked

Voters
156. You may not vote on this poll
  • 0-19,999

    2 1.28%
  • 20,000-39,999

    2 1.28%
  • 40,000-59,999

    6 3.85%
  • 60,000-79,999

    24 15.38%
  • 80,000-99,999

    34 21.79%
  • 100,000+

    88 56.41%
Page 1 of 14 1 2 3 4 5 11 ... LastLast
Results 1 to 20 of 269

Thread: Cracked 0331 cylinder head castings

  1. #1
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default Cracked 0331 cylinder head castings

    Those of you who own '99+ 4.0 WJ's, XJ's, and TJ's who've been affected by this problem, please post the mileage on your engine when the head was discovered to be cracked and the build date of your Jeep (check stamp on driver's door). I'd like to compile a database of Jeeps affected by head cracking problems.
    Please also give details about how the problem was discovered, the symptoms your engine was experiencing, and how it was fixed.

  2. #2

    Default

    build date 10/99, symptoms were: loosing coolant at a constant/slow rate, heavy muck layer inside valve cover/under oil fill cap. The engine would heat up, and the micro crack would not open until a certain temperature was reached thus absolute diagnosis was difficult(for the service manager) at first. The service manager and I had many arguements, he replaced rad cap, a couple times. He was lazy and did not want to pull the head to make sure it was cracked right away and insisted on wasting time/parts and making me go back after adding coolant each time. It started at about 50K miles.

    no performance issues at all before replaced the head, did not use casting 0331 but 7160 this time and no issues. There should have been a recall on the 0331 heads. Luckily mine was still under warranty with the dealer at the time of replacement. good luck!

  3. #3

    Default

    2000 XJ Sport, build date 03/2000 i believe. Bought the Jeep with 82,000 miles. Approaching 85-86k miles I started noticing low oil pressure (<10psi) at idle after 20mins+ of highway driving. Soon afterwards I began to notice a chronic overheating problem that could not be traced to failure of any cooling system components. Eventually tracked it down to a miniscule crack in the top of the head between the #3 and #4 cylinders, leaking small amounts of coolant into the oil (only after fullly heated to temperature) and causing exhaust gases to migrate to the cooling system. This crack was NOT visible via a Magnaflux procedure done by a trusted machine shop.

    I replaced it with another crack-free 0331 head and now carefully watch the engine temperature... the engine bearings probably need replacement at this point though, I'm just barely within spec at temperature (13psi at idle).

  4. #4
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    Quote Originally Posted by Rustler Dude
    Wow, I was never aware that I was at risk for the head cracking. I would like more info on this though.... my build date is 9/99, but nothing is cracked yet.
    The head cracking issue seems to be the result of several bad castings and I can only speculate that the cast iron used in one large batch made around the year 2000 must have been of poor quality.
    The area between the no.3 and 4 exhaust ports is the hottest part of the head and is subjected to the largest temperature fluctuations, making that the area most prone to crack.
    The first sign of a problem is unexplained loss of coolant. If there are no external coolant leaks, remove the oil filler cap and look between the valve springs of the no.3 and 4 cylinders. A crack is usually too small to be seen with the naked eye but you WILL see crusts of coolant in that area and that's a telltale sign.
    If the crack is between an intake port and the water jacket (or between the combustion chamber and water jacket), the engine might run like it's on 5 cylinders. Check the plugs and if one of them has less carbon than the others with traces of coolant, you'll know which cylinder is affected.
    If it's between an exhaust port and the water jacket, you'll have steam coming from the exhaust but the engine will run fine.
    If the crack is only between the water jacket and the crankcase, you'll only have the mystery loss of coolant with the engine otherwise running well.
    Left neglected, enough coolant can accumulate in the crankcase to contaminate the oil and result in accelerated main/rod/cam bearing wear, manifesting as low oil pressure.

    Quote Originally Posted by Taz
    build date on mine is 10/98....am i affected?
    Probably not, but keep an eagle eye on the coolant level and the temp. gauge.

  5. #5

    Default

    Quote Originally Posted by Dino Savva
    Those of you who own '99+ 4.0 WJ's, XJ's, and TJ's who've been affected by this problem, please post the mileage on your engine when the head was discovered to be cracked and the build date of your Jeep (check stamp on driver's door). I'd like to compile a database of Jeeps affected by head cracking problems.
    Please also give details about how the problem was discovered, the symptoms your engine was experiencing, and how it was fixed.
    Please clarify:
    A) What is "99+', who should be affected/post their mileage and poll?
    B) Where is the head casting number? Is my understanding (not sure though) that most problems appeared with a particular casting number. Where do we find it?

    Thanks,
    liviu

  6. #6
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    Quote Originally Posted by liviu165
    Please clarify:
    A) What is "99+', who should be affected/post their mileage and poll?
    B) Where is the head casting number? Is my understanding (not sure though) that most problems appeared with a particular casting number. Where do we find it?

    Thanks,
    liviu
    The head casting number is stamped on the driver's side at the top somewhere opposite cylinder 3. The 0331 head appeared on '00-'06 models though some '99's may also have it.

  7. #7

    Default

    Hi, new to this board.

    Discovered crack head @ ~127,000 miles.

    2000 Jeep Cherokee 4.0L...build date 2/00.

    I discovered it due to loosing coolant from the reservior...had to refill every week. Also discoved coolant around head...in between the cylinder 3 and 4...and spots of coolant under the oil fill cap.

    thebrick.

  8. #8

    Default

    Oh, have not fixed it as I don't have the time or money...put some 'old timey' block seal recommended from a guy at Winchester Auto Parts...seems to be holding it back for now...

  9. #9
    Mostly Harmless
    Join Date
    Dec 2004
    Location
    DFW Texas - land of the neverending GRIDLOCK
    Posts
    113

    Default

    Mine seems to be cracked as well - 84,000 miles. Loosing coolant VERY slowly, and a suspect looking area under the oil filler cap. Here is my question - since I've got a 2000, (build date Aug 99) with the coil pack, can I use an earlier cylinder head? I don't think that they have the coil-pack mounting bosses, but I'm not sure - anyone else done this?
    Will work for sex

  10. #10
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    Yeah, your best bet would be to go for a '96-'98 head with casting no. 0630. It doesn't have mounting bosses for the coil pack but it shouldn't be difficult to find a creative solution to that problem.
    Before you splash out for another head, make 100% sure your existing head really IS cracked. Spots of coolant or a chocolate brownish emulsion will give clues.

    1992 XJ 4.6L "Poor Man's" Stroker
    202rwhp @ 4700rpm (248bhp)
    258rwtq @ 3400rpm (311lbft)
    1/4 mile: 14.63 @ 94.4, 3450lb curb
    AX15, NP231, D30/D35
    Jeep Performance, Jeep Tech, Junker to Stroker

  11. #11
    Mostly Harmless
    Join Date
    Dec 2004
    Location
    DFW Texas - land of the neverending GRIDLOCK
    Posts
    113

    Default

    Quote Originally Posted by Dino Savva
    Yeah, your best bet would be to go for a '96-'98 head with casting no. 0630. It doesn't have mounting bosses for the coil pack but it shouldn't be difficult to find a creative solution to that problem.
    Before you splash out for another head, make 100% sure your existing head really IS cracked. Spots of coolant or a chocolate brownish emulsion will give clues.
    Cool - I'm planning on verifying with the leak-detection dye - I would think I could detect even a tiny leak with that in the system. Any thoughts on this?

    I guess I'll have to build a mounting system of sorts for the coil packs, because there is NO way I'll go back with the 0331 casting if it's cracked! Thanks for the info .... :gtar:
    Will work for sex

  12. #12
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    The jury's back. I collected all the data from the polls that I posted on other boards and here are the results:

    Out of 25 cases of reported cracked heads, the mileage at which they occurred is as follows:

    0-19,999 = 1 (4%)
    20,000-39,999 = 2 (8%)
    40,000-59,999 = 3 (12%)
    60,000-79,999 = 8 (32%)
    80,000-99,999 = 6 (24%)
    100,000+ = 1 (4%)
    Mileage unknown = 4 (16%)

    The most disturbing fact is that most of the heads are cracking when the engine's outside the warranty period, forcing the owner to foot the bill for a replacement. Had most of the heads been cracking inside the warranty period, the stealerships would have been replacing them free of charge and this might have forced DC to issue a recall if large numbers of cracked heads were being reported.

    The breakdown (pun intended) of the Jeep models that suffered cracked heads was as follows:

    '00 XJ = 15 (60%)
    '00 TJ = 4 (16%)
    '00 WJ = 1 (4%)
    '01 XJ = 1 (4%)
    '01 TJ = 2 (8%)
    '02 TJ = 1 (4%)
    '99 XJ = 1 (4%)

    From those results, I can conclude that:

    1. The year 2000 model was by far the worst affected (80% of cases). Anyone who has a 2000 model 4.0 Jeep (especially an XJ) should be on the alert and check the coolant levels frequently. Later models have a much lower incidence of cracked heads and none have been reported from '03 onwards. Can owners of later models take comfort from that?

    2. Perhaps DC knew about the 2000 heads being problematic and the 2001+ heads may be more immune to cracking but can we be sure of that? Remember that most 0331 heads are cracking when the engine's past 60k miles (the peak is between 62-92k miles) and most of the newer engines won't have reached that mileage yet. Therefore there's still a chance that the newer heads could crack sometime in the future.

  13. #13

    Default

    I never had mine on there long enough to crack. I took it off at about 80k miles because of a head gasket leak. Replaced it with a 98 head. Anyone want it I have a good 2000 0331 head.

  14. #14
    Registered storm_boy23's Avatar
    Join Date
    Nov 2005
    Location
    Kitchener, Ont. Canada
    Posts
    19

    Default

    build date 5/00
    purchased with 47 000 miles on it, notices coolant loss pretty much 2 weeks after i got it. took it in about 2 months later, after much trial and error, and had the head replaced on warranty.

    now have low oil pressure at idle, holds around 10 psi
    gettin that fixed under warranty too.

  15. #15
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    Another unhappy tale from http://www.naxja.org/forum/showthrea...024#post742024 :

    Quote Originally Posted by jmelby
    2001 with 67,000. I should find out later today what the scoop is...
    EMERGENCY!!! Head is cracked - casting number 0331 on a 2001...

  16. #16

    Icon312

    You can add another 2001 TJ to your poll... 93,000 miles when discovered... not sure exactly how long it has been cracked, but just noticed the leak recently... i don't know what the casting number is yet it's at the shop and I forgot to ask about it when I talked to them... my warranty just ended in august 05, so that sucks... but anyway, just thought i'd add to your survey!

    what alternate heads will fit on an 01 TJ?


    Quote Originally Posted by SilverXJ
    I never had mine on there long enough to crack. I took it off at about 80k miles because of a head gasket leak. Replaced it with a 98 head. Anyone want it I have a good 2000 0331 head.

    have you had it checked for cracks? is it free? will it fit my TJ? and would you be able to ship it to houston? i would pay for shipping... just thought i'd ask!

    Jason
    2001 TJ

  17. #17
    XJ Moose Rustler Dude's Avatar
    Join Date
    Dec 2003
    Location
    Long Island, New York
    Posts
    2,692

    Default

    Great...i'm now in the peak "season" for head cracking. 64k miles on it now.

    For those who use earlier heads on a 2000 or 2001, what do you do for the coil packs? I mean, i can always upgrade to an aluminum head, but thats pricey.
    Sold all jeeps.

  18. #18
    Stroker Fever Dino Savva's Avatar
    Join Date
    Jan 2000
    Location
    Al Ain, UAE
    Posts
    12,673

    Default

    Quote Originally Posted by gpinjason
    ... my warranty just ended in august 05, so that sucks... Jason
    2001 TJ
    Sucks bigtime but unfortunately since most heads are cracking beyond the 60k mile mark, there are many others like you whose Jeeps were outside the warranty period when the head cracked.
    Replace it with a 0630 head from a '96-'98 model. It won't have coil pack mounting bosses so you'll have to get creative.

  19. #19

    Default Coil rail/pack mounting

    I used some stainless steel straps from the valve cover bolts (the ones with the studs) to the coil rail. I also shaved a bit of the mounting busings off the coil rail and JB welded some bolts to it so I didn't have to twist my arm up under there to un bolt it.

    My webshots gallery in my sig has some pics if intrested.

    -Chris




    If anyone is intrested I have a good used (hasn't cracked) head from my 2000 available. Came off ay 80k miles.

  20. #20

    Default

    Quote Originally Posted by Dino Savva
    1. The year 2000 model was by far the worst affected (80% of cases). Anyone who has a 2000 model 4.0 Jeep (especially an XJ) should be on the alert and check the coolant levels frequently. Later models have a much lower incidence of cracked heads and none have been reported from '03 onwards. Can owners of later models take comfort from that?

    2. Perhaps DC knew about the 2000 heads being problematic and the 2001+ heads may be more immune to cracking but can we be sure of that? Remember that most 0331 heads are cracking when the engine's past 60k miles (the peak is between 62-92k miles) and most of the newer engines won't have reached that mileage yet. Therefore there's still a chance that the newer heads could crack sometime in the future.

    IIRC, someone in the know said that the 2003+ XJ head was modified to prevent cracking. I just don't remember where. It was probably one here though.

    -Chris

Page 1 of 14 1 2 3 4 5 11 ... LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Jeep Parts | Jeep Accessories | Trektop NX | Jeep Seat Covers | Jeep Wrangler | Jeep Wrangler Parts | Jeep Wrangler Accessories | Bestop | Jeep Tires | Jeep Stuff | Jeep Wrangler Tires | Jeep Wheels