04 to 02 Engine swap

[KidsKJ02]

I have an 02 limited in decent shape with a blown motor and rusted out 04 with a good motor, I’ve already pulled both motors and broke down the blown one. I was hoping this was a straight forward plug and play option but after much research I’m seeing I will have to change out the crankshaft reluctor ring and high side cam note from the 02 to the 04 to make the 02 ECM think it’s still running an 02, I see this to topick has been covered however, has anyone simply swapped out the computers instead as to not have to break down the running motor and remove the crank shaft to change out the reluctor ring? People talk about reprogramming the 02 ECM and all but I have the 04 ECM and everything else to go with it. Really don't want to tear down the good motor… thanks for any advice.

 

[KJowner]

You would need to swap the immobiliser over as well, it's coded to the ECU, not sure if any of the other modules are + is the gearbox the same? I the v6 had 2 different gearboxes but I don't know when. I'm sure someone with a V6 will be along shortly, mine are CRDs

 

[KidsKJ02]

Ok thanks. Yes it’s the 3.7 V6. Not sure on the gearbox? will have to research that a bit more. There are several forums on the net covering this as it seems pretty common as the 2002 3.7 is pretty hard to find these days however, every one of those goes into depth on changing out the timing hard parts. In all my shade tree wisdom, I would assume it would be so much easier simply swapping the PCM proving the plugs are the same. I was on the fence of just rebuilding the 2002 block or finding a running donor. Had I known I’d be doing a full break down on the donor too, I would have just rebuilt the 2002 ‍.

 

[KidsKJ02]

PCM swap isn’t going to work. 02 has 3 plugs 04 has 4. Darn looks like I’m splitting another engine open.

 

[KidsKJ02]

Also I’m thinking I may have posted this on the completey wrong place/page as its nothing but crickets my apologies. I thought I saw some heavy engine work posts on here in the past. If anyone on here has ever swapped a newer 3.7 into an older chassis please dm me or email me. I’ve rebuilt plenty of engines years ago and I’m trying to justify completely tearing down this engine only to replace a crank note and not doing a master rebuild, unless I’m missing something here and there’s another easier way. Thanks so much.

 

[lfhoward]

Sorry for crickets! I just think most people have never done that kind of engine work before.

I am on my second engine in my 08. In my case the Jeep was under 100K miles when the engine blew, and so I went with a Jasper Remanufactured 3.7. Jasper eliminates certain weaknesses in the original engine (fragile valve seats, for example) and provides a 3 year 100K warranty including labor. Probably in your situaton (or if I needed an engine now) I would be looking into replacing it myself just as you are.

 

[KidsKJ02]

Yeah, I looked at jasper and a few others, that’s what I wish I could have done too however, I just can’t justify dropping a $3200 short block into a $700 car. I just pulled the reluctor out of the blown motor today Confirming there’s no way to get that out without removing the entire crank shaft. Good times for sure!

 

[lfhoward]

Yeah, I looked at jasper and a few others, that’s what I wish I could have done too however, I just can’t justify dropping a $3200 short block into a $700 car. I just pulled the reluctor out of the blown motor today Confirming there’s no way to get that out without removing the entire crank shaft. Good times for sure!

Absolutely, the math needs to make sense. I love your avatar picture showing engines removed from your two KJ’s. That’s a nice touch, even if it is a pain to tear them down for the reluctor rings. I’d love to see your progress with the swap, if you want to continue posting here.

 

[Shankster]

Yeah, I looked at jasper and a few others, that’s what I wish I could have done too however, I just can’t justify dropping a $3200 short block into a $700 car. I just pulled the reluctor out of the blown motor today Confirming there’s no way to get that out without removing the entire crank shaft. Good times for sure!

I put a $850 short block from Cars & Trucks Engines 4Less in my 02 and so far so good.

2002 2003 Dodge Ram Jeep Liberty Nitro 3.7 Engine Short Block JTECH

Contact us for price and additional information THIS IS A COMPLETELY REBUILT SHORT BLOCK ASSEMBLY, THAT INCLUDES NEW PISTONS ,RINGS ,BEARINGS(MAIN,ROD,THRUST WASHERS AND BALANCER). FREEZE PLUGS AS …

www.flengines4less.com

They were really good to work with and worked hard to find an inexpensive shipping option for me. I also bought a rebuilt head from them that I wasn't quite so thrilled about. It seems to work OK but the camshaft and caps had a lot of corrosion and are badly pitted. Bottom line, they do good work but seem to use some cores that should have gone to the scrap recycler. Given their low pricing though I think it's worth the risk if you're on a budget and I'd go back to them in a heartbeat.

 

[KidsKJ02]

I put a $850 short block from Cars & Trucks Engines 4Less in my 02 and so far so good.

2002 2003 Dodge Ram Jeep Liberty Nitro 3.7 Engine Short Block JTECH

Contact us for price and additional information THIS IS A COMPLETELY REBUILT SHORT BLOCK ASSEMBLY, THAT INCLUDES NEW PISTONS ,RINGS ,BEARINGS(MAIN,ROD,THRUST WASHERS AND BALANCER). FREEZE PLUGS AS …

www.flengines4less.com

They were really good to work with and worked hard to find an inexpensive shipping option for me. I also bought a rebuilt head from them that I wasn't quite so thrilled about. It seems to work OK but the camshaft and caps had a lot of corrosion and are badly pitted. Bottom line, they do good work but seem to use some cores that should have gone to the scrap recycler. Given their low pricing though I think it's worth the risk if you're on a budget and I'd go back to them in a heartbeat.

Darn, I wish I would have checked this reply months ago... I couldn't find a new short or long block anywhere for under $2500. I just completed all the internal parts swap and dropped the motor back in bolted it up, only to find the 04 flex plate will not align with the 2002 torque converter bolt locations, so it looks like it s coming out again, what's hard to believe is all the indept write ups on this forum among others on this process but not a one person mentioned the torque converter.