Options for my KJ after 205k miles?

[jayrenegade]

Hey everybody, I just joined today to hopefully find answers and share ideas. I have an 03 Liberty Renegade that has been an extremely dependable and fun vehicle. I bought it in 06 with a little over 50k miles and had little trouble from it at all. I now have 205k miles on it and I know that things are going to start giving out on it soon. Instead of buying another vehicle I think I would rather spend a lot less money on just revamping this one. I'm considering options on replacing the engine and transmission. My only complaint is that the 3.7L is a bit weak at 210hp and I would like to get more power and torque if I'm going to keep it for another 5 years at least. Any ideas and suggestions are greatly appreciated.

 

[1BADKJ]

Drop in a hemi.

 

[hectikart]

4.7L swap has been done...There's a decent amount of info posted on here already if you search. HEMI would be sweet, but that would be quite a project...I won't say impossible, but maybe barely possible.

 

[Kirksjeep]

How much $$ are you willing to drop into a 10 year old Jeep? I would think a moderate expense would be to find a used 3.7, have it rebuilt and same with the transmission. Do you have the 45rfe or 42rle transmission? In 03 they switched. If you want more power, get a chip, exhaust and intake, and see what the engine builder can do. This also avoids custom parts and electronics which to me reduces the reliability.

A hemi, or 4.7 is possible but it all costs money$$$$$

 

[1BADKJ]

Hemi would be SOOOOOOO sick. saw one in a JK at pa jeep show. Very nice work. They had an ECM and harness from Turn key.

 

[hectikart]

How much $$ are you willing to drop into a 10 year old Jeep? I would think a moderate expense would be to find a used 3.7, have it rebuilt and same with the transmission. Do you have the 45rfe or 42rle transmission? In 03 they switched. If you want more power, get a chip, exhaust and intake, and see what the engine builder can do. This also avoids custom parts and electronics which to me reduces the reliability.

A hemi, or 4.7 is possible but it all costs money$$$$$

Definitely agree that you're talking major $$ to do an engine swap. As far as getting more power out of the 3.7, don't bother with the intake, exhaust, or chip...complete waste of money.

If anything, re-gear to 4:10, probably best performance mod available. You should be able to get a rebuilt 3.7L for about $1000-1500. You would spend more than that just on the mod to get the KJ to recognize a different engine.

 

[TwoBobsKJ]

If you're wanting a donor motor to replace the 3.7 look for an engine from a Chrysler product other than a Liberty. Engines in Dodges, Ram trucks, etc are about $1000 cheaper than a Liberty-specific engine.

FYI, you can use an engine up to a 2011 - but you'll need to swap out the left cam sprocket, the reluctor ring on the back of the crankshaft, the intake manifold and the oil pan.

To save having to pull your Jeep engine apart to get the cam sprocket and reluctor ring out of it, I bought a kit from Engine-Guru.com that includes the sprocket, ring and a blocking plate for the EGR valve (that your '03 doesn't have.)

If you have an '05 or later Liberty you don't have to worry about swapping the sprocket or ring as yours already uses the new NGC computer.

Bob