Crazy engine swap

[Rudy]

I'm wanting to put 5.4 where a 4.6 was has anyone ever done this or have I lost my mind to try and do this

 

[Habbibie]

A hi before that question couldn't hurt would it?

 

[Rudy]

I don't know everyone says it can't be done

 

[juan214]

May need to flash the PCM

 

[Rudy]

Could I change PCM to a. 5.4

 

[drewactual]

the only thing that may give you trouble as i understand it is the transmission as most 4.6's were running a 4r70/75's and 5.4's 4r100's. the TCM requires different wiring and connections, and the TCM for the 4.6/4r70/75 isn't capable of producing the voltage required to operate the 4r100.......... so..... the PCM can likely be flashed but the TCM will require one intended for a 4r100 (if in fact that is what is behind that particular engine/build) as well as it being flashed for the pressures of a Expedition (torque management; valve body/solenoid pressures)... otherwise, you're in for a choppy ride.

what year are you talking about?

if you're dropping a 2v 5.4 in the place of a dohc engine, the PCM will have to be swapped- likely true with any of the variations from 4.6/5.4 2v/3v/4v and sohc/dohc.... so.. bank on a PCM flash/swap at a minimum, and a PCM+TCM possibly/likely.

Romeo and Windsor engines are different, too- not that it should impact for a simple (simple?) swap, but.... be aware of that, as well.

 

[Rudy]

Thanks I'll look for that . All my connections on my tranny hooked up with a problem but if any thing happens I'll let ya know. I should be done by Saturday afternoon. So we'll see.

 

[Timm1687]

Was thinking about doing this and am very interested myself. Keep us posted! Any pictures or anything of the process?

 

[Rudy]

Well guys I found 1 thing so far that was different the bracket from the transmission to the exhaust pipe won't fit you have to cut off 1 1/2 inches off of it to fit