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'00&'01 engine vs prior yrs-worth more $$ ?

spacomponents

NAXJA Forum User
I'm shopping now for an XJ and my question is this:

Is it worth spending a little more for an '00 or '01 to get the low emission engine. I've read the improvements were good, adding a few H.P., better intake, etc.

I just don't want to pass on a good '99 if there's no significant benefit.

:geek:
 
The O2 sensors are not on the cat in the 00 and 01 model years, so exhaust is easier to work on and a little cheaper, and the ignition is far hotter and more reliable on the 00 and 01 years. There is a problem that crops up on the head of those years more than anyone likes, but it isn't all of the heads that crack. Mine did and I got it replaced under warrantee, still working for me, knock on wood.
 
Fish'nCarz said:
The O2 sensors are not on the cat in the 00 and 01 model years, so exhaust is easier to work on and a little cheaper, and the ignition is far hotter and more reliable on the 00 and 01 years. There is a problem that crops up on the head of those years more than anyone likes, but it isn't all of the heads that crack. Mine did and I got it replaced under warrantee, still working for me, knock on wood.
If it wasn't for the heads cracking, I would drop an 00 or 01 4.0 in my 1990, but the head is enough to leave a bad taste in my mouth. My bro has an 01 and his is at 93k and not cracked yet, I've still got my fingers crossed for him. His sure does run quiet and clean compared to my 90 though, I will say that.
 
I own a 1990 and a 2001, both 4.0 engine and auto tranny. The 2001 uses four oxygen sensors (two before the cat, two after) which is obscene engineering. There are two 'pre-cats' and another main catalytic converter. This is a lot of expensive stuff, when it starts to need replacing. The 2001 (and 2000) also use the weaker low pinion front axle, while up to 1999 uses the stronger high pinion design. There are two positives to the 2000 and 2001 model years: distributorless ignition and improved intake design (better flow). The 00/01s also use the 0331 head, which may crack. The more time Chrysler has to mess with Jeeps, the worse the result. Many consider 1999 the optimum model year, with most of the improvements but before the serious bummers. I actually like my Renix 1990; my wife drives the 2001.
 
Well, thanks for your input. My idea has been to go with the '00-01 and get the quieter, cleaner engine, and swap out the low pinion for a high pinion. I think that would be easier than buying a 1999 and trying to add the intake and ignition, because I'm sure that would mean '01 computer, wiring, basically a nightmare, right? :bawl:
 
I've had no issues with the 2 00s thats I've had. I swapped in a Hp like you said you wanted to do and everything works fine and dandy. 00+01s are distributor less and sometimes more expensive to work on. Also aftermarket headers are scarce and expensive. You may get a strange running called heat soak if your constantly turning it on and off (to do errands or what have you) but it happens in very few. I truly would recommend just getting a 99 you will have a HP D30, your head won't be sketchy, and you will have the distributor and cables. They don't run noticably different and the 99 has a lot more going for it in terms of reliability and lower cost for exhaust type stuff.

-AR
 
mrrbby said:
my 99 has the intake, but the cap and rotor ignition.


X2 - No distributorless ignition on my '99
 
You could pick up an older model with the hp axle, and install the 99 and up intake. I plan on doing that upgrade to my 96. Of course I found an intake after I replaced the entire exhaust, header included.:doh: The intake was already off the engine, and cost a whole $20.00 .
 
Sorry, 99 has the Old ignition new manifold and HP axle, sorry.

I can't say if the manifold makes a difference, I port matched my head at the same time and it made a bit of a difference. I can't see why you would go through the trouble of changing the manifold and not port match the head though.
 
I believe that the intake swap has been covered in the modified forum. I picked up mine because it was cheap, and it was already off of the motor. Plus, it would be a spare for my 99 if I ever needed it. I'll find out this summer when I install it.
 
4xBob said:
I own a 1990 and a 2001, both 4.0 engine and auto tranny. The 2001 uses four oxygen sensors (two before the cat, two after) which is obscene engineering. There are two 'pre-cats' and another main catalytic converter.

Only on vehicles with California-compliant emissions, though. My last one had California emissions and exactly this setup; the current one is Federal and only has a single pre-cat, one main cat, and two oxygen sensors (IIRC). It sounds like the standard export version for Canada may have been to California spec.
 
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