4.2L Interchange

[danj]

I have a 2004 Trailblazer. I bought it as a crashed vehicle from a friend. He claimed to have drove the truck on and off of the trailer without issue. So to make a long story short I spent a ton of time and money putting a new front clip and other various parts on. I finally fired it up. The truck ran, but poured coolant out of the exhaust just as fast as you could pour it in to the radiator.

That night my sister got rear ended in her 2007 trailblazer. The insurance company totaled the truck. A semi tried to pass her on an on ramp and ended up dragging the trailer down the driver side. It ripped the quarter panel off, but the truck can still be driven. I bought the truck back for parts.

Both trucks have a 4.2L. My thoughts were to take the motor out of the 2007 and put it in the 2004. I've heard there are some differences that make the motors not interchange from one to the other. Does anyone know what the differences are?

Thanks in advance for any information!

 

[Sparky]

There is a PCM difference but I know people have put the 06+ engine into the 02-05 trucks in the past. So yes it can be done but what exactly needs changed to make it work I'm not positive.

 

[jimmyjam]

trying to google info but I find conflicting information whether they switched to 58x crank reluctor in 2008 or 2006

you'd definitely need to reuse the fuel rail because they switched to in-tank fpr. the other unknowns to me at least are any changes to VVT and coil packs and how they'd affect compatibility.

 

[BlazingTrails]

Of you have the donor vehicle you should be good to go. You should just need to keep the harness with the 07 engine and the transmission. And keep the pcm and TCM with the 07. You would need the fuel rail from the bad engine as stated above. Imo

 

[jimmyjam]

no guarantees that swapping harness/pcm won't be a can of worms...

 

[limequat]

07 goes into 04. As mentioned keep the fuel rail, harness, PCM. May have to take off the AIR solenoid. But, they're both 7x cranks.

 

[danj]

Thanks everyone. I have to pick up the 07 from the collision place tonight, so I can better assess the damage then. From the pictures I saw of the truck it looked like the quarter panel got ripped off, but it didn't touch any crucial driving component. If it just needs a new quarter put on I may fix both trucks by getting another donor. My only issue with that is at this moment I have over 20 vehicles in my driveway. I don't know if my old lady will let me live if I brought home another, We will have to see tonight. I'll post some pictures for opinions later.

 

[RayVoy]

at this moment I have over 20 vehicles in my driveway.

Should be easy to hide it (in plain sight) if there are that many.

 

[danj]

You would think so, but my old lady has eyes like a hawk.