Engine Question (2002)

[zraffz]

My girlfriend recently developed a bottom end knock in her 2002 Jeep Liberty. At this point in time I am not interested in rebuilding the motor (although I am capable of it and probably will check out the bottom end when the motor is out). When her motor was checked out it was out of oil. I originally wanted to check her heads out and purchase a local short block but the deal fell through.

I found a 2006 Liberty motor, still the same 3.7 liter engine but I am being told it will not work with her vehicle because her vehicle was year specific and requires a 2002 model motor.

Can anybody tell me what the differences actually are and what motors I can actually use?

 

[ridenby]

Have read the difference but don't recall details. It is in here,not sure what/how to search it. Think it follows the transmission change,45RFE to 42.

 

[LibertyTC]

As long as your 2002 block and heads are rebuildable , you are better off to do that or as already stated a new 2002 long block. There was so many changes from 02 and onwards, including the the fact the 02 bolted up only to a 45RFE, and the associated electronics programming, I think it is safe to say if you are trying to find another motor, it must be from an 02.

 

[yellocoyote]

Think it follows the transmission change,45RFE to 42.

That's what I think too... and I'm not sure if it would 'match' with the vehicle's computer.

 

[04Liberty]

It would be worth your while (or hers?) to rebuild the original if it can be. I would put the 05+ cams in it if the opportunity arose, they are slightly more aggressive and would go well with the custom tuning I have. On a positive note, you have a much better transmission if you have the 45RFE.

 

[Liberty02sport]

My '02 dropped a valve due to a broken valve spring and needed a new motor. Warranty company threw a fit 'cause they couldn't find a salvage motor to replace it with and had to go with a new long block incl. the heads, so I'd say the differences are fairly substantial.

 

[04Liberty]

I knew there was a sticky for this:
http://www.jeepkj.com/forum/showthread.php?t=42031