I bought a 2007 trailblazer 4.2 v6 with a bad engine and bought a replacement engine from a local junkyard that will not take back it is from a 2003-2005 I know that it has been done with a 2007 engine into a 2003-2005. I also understand that this is a down grade but what will I need to change to make the 2003-2005 engine work in the 2007
2007 Trailblazer With Bad Engine Bought A 2003-2005 Engine How Can I Make It Work
- Thread starter Shadohc39
- Start date
Mooseman
Moderator
From the FAQ:
https://gmtnation.com/forums/threads/06-4-2-swap-into-an-05.16885/
The only real issue is relocating the temp sensor wiring from the '07 location at the rear right of the block to just above the thermostat.
https://gmtnation.com/forums/threads/06-4-2-swap-into-an-05.16885/
The only real issue is relocating the temp sensor wiring from the '07 location at the rear right of the block to just above the thermostat.
Mooseman I did read that I would need to extend the coolant sensor wiring but also seen that I would have to get the pcm from the earlier engine is there anything else I would need would hate to put it in and not run
Mooseman
Moderator
Why would you keep the older PCM? Use the one from the '07. You might have to swap some parts from the '07 engine to the '05 for connector compatibility. If you keep the 05 engine complete (no head swap like in the other thread), you'll likely just need to use the 05 coils' wiring and connectors to work with your 07 harness. Might have to do the same for the injectors if they the engine is 02 to 04 (05+ are all the same).
Ok is there a valve on the side of the head on the 2007 not sure what it is called will that interchange on the older motor for my 2007
Sorry I thought I read that you need the pcm from the motor to make them work together
Sorry I thought I read that you need the pcm from the motor to make them work together
limequat
Member
- Dec 8, 2011
- 520
Nope and yes you can swap over the SAIC solenoid. Better yet, by a tune from me and disable it 
