Is it safe to to throw a 2004 5.9L Cummins into a 2005 5.9L Cummins when they have different wiring harness ends as long as you swap out the ends on the harness to work out. Or is the wring harnesses two totally different programs and are going to display errors to the engine all the time. Also will the engine run rougher if this is the case.

 

Totally different ECM design as well as a few internal changes.

Long story short: It won't work.

 

Put the 2005 ECM on the 04 Engine it won't know the difference, if the injector plugs are different just use the valve and rocker cover off the 05 all is good.

 

Agree, the engine won't know the difference. However, the ECM will, and as the ECM controls everything that makes the engine run, it's going to have issues. I think if he did this, he'd at least end up with constant CELs, and at worst it may never run right. I know the 04.5 and up ECM monitors a lot more data points than the the previous years, and it uses that info to control engine function to much closer limits...if the hardware on the engine doesn't support the software, the software isn't going to let the engine work as intended.

 

The 04 and 05 have the same sensors the ecm won't even know you changed the engine, you will want to use the 05 turbo and engine wiring harness tho. The only diffrance in the engine is the pistons, injector tips, turbo, valves and valve seats all else is the same.

 

It will work, just not exactly right. The injection patterns, timing, etc is different and that may show as excess smoke and power differences.

Cannot use the 04 ECU because it is VIN locked to the truck. The 05 ECU simply doesn't case what engine is there as long as all the connections are made. The only differences will be around combustion.

 

If you use the 04 motor you will need to use the 05 ECM, sensor, and turbo.

You will also need to do something to add timing, like a Smarty Jr, becuase the valve seats in 03-04 don't like crazy heat and the stock 05 tuning will run EGT's several hundred degrees higher than the 04 did.

 

It will work... Just be sure if the truck ever needs new injectors it gets 04 nozzles... 05 nozzles in an 04 will smoke under all off idle conditions as the spray patterns are different.

 

I love this place...learn something new every day!

 

I put a 03 motor in a 05 truck and used 05 computer wire harness and turbo trucks runs really good and smooth but does seem to be lacking in top end power just like a motor with retarded timing would....I ordered a smarty jr. Iv never used one before how much do I advance timing?

 

I would run the timing on TM2 or TM3.

 

Thank you

 

Not only were there 2 different Dodge Cummins engines available in 2004, who knows what injectors and pistons are in the 2004 and in the 2005 engine for that matter.

These engines and trucks are getting really old. Over the years engines could have been swapped or rebuilt or cylinder heads swapped or rebuilt or who knows what.

I recommend that you 1st determine exactly what injectors and pistons are in the replacement engine before you do anything else.

This will determine what the next steps are required.

 

What sensor

 

I put a early 04 on my 05 used 05 wiring ECM and turbo runs horrible sounds like death just got a smarty jr in this morning do you recommend any particular settings