I bought my Jeep cherokee about 3 months ago, and I've been using this forum for info ever since. Thanks for all the great info!


Its a 2001 XJ with 125k miles on it.

As the title says, I just found out I have a cracked head... while the engine is running, if i look through the oil fill hole, I can see coolant weeping in from the head. I knew that the cylinder head cracking was a problem for 2000-2001 4.0L when I bought the jeep, so I have been checking coolant level and oil several times a week, and just noticed yesterday that there was coolant imulsified with the oil and found the crack in the head, so hopefully I found it early enough. I've got the jeep parked until I get it fixed.

I've found an 0331 head from J&C Enterprises, and they say that it has been reinforced in the weak areas. From what I've read on other threads, it seems to be a decent head to use. Does anybody have any other recommendations?

This is the first cylinder head i've ever had to replace, so my question is, when replacing the head, what other things should I check while I've got the head off? (or just any general advice while swapping heads.)

Thanks!

 

Personally I have never had to deal with the crappy 0331 head. But from what I have read you can replace the 0331 head with the 0331 TUPY head. This is a head that has had the weak areas reinforced. Make sure to drain the oil as soon as you can. The antifreeze will cause the bearings to fail prematurely. Try not to run here until you do get the repairs done. I know you said that you have her parked until you can repair her. Don't run her as it is or you may end up having to do a bearing replacement.
Welcome to the forum and let us know how the head replacement goes.

 

Unless you are having some other problems, it's pretty much just a simple swap.
Change the oil, run it a few miles, change the oil again to make sure all the coolant is out of it.
Will you be buying a loaded head with new valves, springs, etc?

 

Thanks for the advice guys.

I bought a loaded head from J&C Enterprises that is ready to install. I read on a few other threads that they are pretty decent heads, and it comes with a 1 year warranty. Hopefully it will be here by this weekend so I can get it installed and get back to driving it!

One more question: should I buy replacement head bolts?

 

I wouldn't, but I haven't changed a head in 50-years. Properly torqued, should be fine.

 

Here on the forum I've read the head bolts can be used twice, the bolt heads get marked with paint the first time. Reason is they are stretched on install, and you can't stretch them too many times. (one of them needs sealant because it goes in the water jacket/coolant)

You will find plenty if little stuff to check while changing the head. I'd allow plenty of time. Wires, hoses, vacuum lines, yada yada...

The "tupy" head is a revised casting. I've read the "tupy" is somewhere under the oil filler cap.

Have fun!

 

I would, you are already in there, and who knows how many times they have been torqued...If done before in someones driveway, they may not have marked the bolts with paint. A small price to pay for peace of mind knowing it was done properly. Also make sure you get the loctite on the right bolts if you do replace them as mentioned above, and follow proper torque sequences and values of course....it is a fairly straightforward job. BTW, do you have a FSM for your year? If not, get one in pdf format for around 15 bucks online. Everything you need is in there, also money well spent...

 

I've done at least a dozen heads and always used the same bolts without a problem. At 125K it's unlikely it's been changed. That said find and price them before you decide, (no China crap). They might turn out to be spendy.

Maybe 5-90 will chime in....

 

+1

To those suggesting replacement, the implication is that the bolt suffered plastic deformation . . . really!!! If so then those bolt(s) were undersized to begin with.

I'd much rather have an old OEM bolt than risk an unknown (China) piece of steel. Pretty easy to put a six star grade mark on any bolt.

 

If they are a torque to yield fastener replace them. I dont buy into the they can be reused once garbage. To me it is not worth the risk of a fastener being stretched.

 

Head bolts/studs are one of the few areas where I won't fudge on specs. Get new ones, they aren't a huge expense.

 

Indeed, BUT are they???

I could see doing "torque to yield" on a throw away rocket, perhaps a bridge, but an automotive engine with infinite thermal cycling, no way.

This is just yet another example of ignorant DIYers not knowing so "if in doubt, replace"!!!

 

$40 for Felpro head bolts, not a huge expense...like I said small price to pay to know it's done correctly

Guess I'm ignorant then

 

Thats my point I wont risk having to pull the head again over 40-50 bucks !

 

$40 bucks doesn't sound bad. I'm sure Hermit didn't mean to offend. Untill "lately", we use to just repair what was wrong. If the brushes in your Alt, or starter were out, you replace them for $2.95. (or go through it for $10). Now with insurance and litigation and high rent and all that, it's "cheaper" to spend $150-$250 dollars for a $3 repair! " I just today bought a bearing #NTN 6203 off Ebay For less than $3 to make a Toyota alternator good to go.

I'm to mad to feel ignorant when I hand them my good starter and $150, when all I needed is a solonoid!

Heck, maybe you can sell those "once used" bolts on ebay for $20!

Best to ya, gonna be a big job if it's your first. You are in good company anyway.