do all the 01's have the 0331 head?

 

yes

 

00-01 yes... for the XJ... 99-02.5 for the wj and I forgot the TJ...

 

where on the head is the number casted on. can i check without taking anything apart

 

if yours is a 01 then its a 0331 head... no doubt about it...

 

dang tht sucks

 

If it is still the factory head, then without question it is the 0331.

To be sure, you can look on the head to verify. Get a rag and clean off the area on the lip of the head, on the drivers side, about halfway back. If you clean it well enough and you shine a good light on there, you can read the casting number.

Are you having any symptoms on your 01?

 

well mine only has 80k on it but when i bought it with 75k it had to rotted freeze plugs. making me think the engine overheated at one time or so. also i think my reserve tank empties slowly ill have to make sure after i do a complete flush next week. im just worried about it

 

just run it till it dies... nothing really you can do... dont let it over heat and try and keep the RPM's down... if it does go out you can find just the revised heads BUT 90% of the time the damage is already done to the cranks bearing so your better off finding a motor from a 02.5 or just say 03-04 WJ just to be sure... they have the revised head already... and reuse your motors stuff... i bought a 99 WJ with the 0331 blown head and put a 04 WJ motor in it... bought the whole WJ T-boned off ebay an hour away for $1k... parted out what was good and made my $1k back...

 

have 00xj since July flush cooling system as planned and change t-stat as well runs at 195 to ckeck for coolant take oil cap off get good flashlight and look down cap between cyl. #3 & #4 for antifreeze I realize these can crack but lack of maintaince plays a part too! The cap idea wasnt mine but I got the info on here so gudos to the members of the forum but I am not about to sell it just cause it might have 0331 head too many plus factors

 

does have the 0331 head ya i would sell either... i would just keep an eye on it and ride it out... i probly wont buy one though knowing this... never know how it was kept before i was to buy...