My Jeep was mfg. in 10/09 I am hoping it does'nt have that dreaded bad head. How can I tell? Fortunately, so far ( 112,000 mi.) no problem.

 

Don't worry about it...just drive and enjoy. Not all of them go bad and, when one does, it's not a crisis. Check your oil often (every day is not a bad plan on a ten year old truck) and take action when/if you find evidence of water.

 

Theres a casting number on the head.

#0331 I believe

http://lmgtfy.com/?q=How+do+I+find+out+if+I+have+the+bad+head+on+the +2000+Jeep+XJ

 

X2, it's not as common as everyone will make you think and when it does fail, it's not catastrophic as long as you catch it fairly soon. Water in the oil (not the white stuff on the bottom of the oil cap) will make the oil look like a milkshake and will destroy the bearings if not repaired so just keep an eye on it. You do check your oil every time you fill your gas tank don't you?

 

I agree that it's not catastrophic as long as you replace the cracked head before coolant damages the cam/rod/main bearing. It's just the inconvenience and the unexpected cost (around $600 for new head and gaskets...I just replaced my cracked cylinder head last week so I know the frustration and cost). Check your oil regularly as suggested. If you see coolant under the valve cover, your head is cracked....most likely between cylinders 3 and 4 (if it's a 0331 head). Look under oil filler cap with flashlight (directly over cyl 3/4).

As far as not being a common problem, I don't necessarily agree with this. Every Jeep owner I know that has a 4.0 2000-2001 (all w/0331 head) has had a cracked cylinder head. When I first called to buy a new head, the supplier was out of stock due to the demand. Go figure....