galaxie08

I have completed the 4.6 to 5.4 swap. The dealers in my area, one will not d a flash and the other says they can't. What hardware do I need to do this myself.
KJ

TheJMC

contact bone of the aftermarket tuners Ie: Superchips, Diablosprot ect and ask them.

DESERT_RACER

Hey guys, one question I've been really concerned about in this swap as I am looking into doing it, is smog. Im in California, and want to know how smogging would go with a 5.4 on a 4.6 VIN number/registration. Does the 5.4 produce the same emissions as the 4.6 readout, or are they different? And if they are almost the same, would the smog shop notice the motor is different from the original off the VIN? Thanks guys especially JMC and Torkum really helpful information.

lowce805

No problem there, emissions outputs are the same.. (smogged twice)
VIN as well nothing will be noticed or checked..
Really the only thing that changes is auto parts.. (oil filter, plugs, sensors,ext..)


*successful 98-4.6 to 03-5.4 swap

DESERT_RACER

JMC, sorry to keep having you explain the same broken record, but the torque converter issue; going from a 4.6 to the 5.4, do you recommend putting a 5.4 converter on the 5.4? Or leave the 4.6 converter and attach to the 5.4? What I'm gathering is you recommend attaching a 5.4 converter on the 5.4 going in because a 4.6 converter could blow the tranny because of the 5.4.
Thanks!

TheJMC

The 4.6 torque converter multiplies torque at a higher factor than the 5.4 converter. This was done ( my best guess ) to over come the lower torque output of the smaller engine. To be safe I recommend using the 5.4 to avoid possibly damaging the transmission from excessive torque.

Frankenstein F150

I just recently completed the 4.6 to 5.4 swap. I have a 2001 that had a bad 4.6 and installed a 5.4 from a '98. Thank you to TheJMC for your well written notes. It made the swap easy and stress free. Still dealing with trying to get the tune for the computer but it runs and drives so for now it's a win.


I did re-use the exhaust manifolds from the 4.6 which give me one unexpected problem. The EGR pipe did not match to the throttle body and I had to bend the pipe as well as drill and tap the throttle body to bolt it up. I also made the mistake of reading over the first recommendation in the notes that told me I needed to use the wiring harness from the truck and not the donor engine. That leads to a few quirks that will make you scratch your head for a minute. For example: an A/C that will not ever shut off and sensor errors.

0477004wd

what about a 5.4 to 4.6 swap in a 2004 7700 4WD?

Cris Czetyrko

I just bought a 98 f150 4x4 had 4.6 swapped to a 5.4 . I have no power to what I believe is the driver side injectors. I find a plug with 4 wires out of 8 cut and spliced. I'm attaching image. Any help wi be appreciated

John Cheramie

I have a 2001 ford expedition 2wd... Im NOT mechanical inclined and I wanna do a motor swap... I currently have a 4.6 Romeo in my expy but I wanna go to a 5.4.... Can someone tell me if I can plug and play or is their a **** ton of things Im gonna have to change to make this work???

As in same wire harness transmission and torque converter or will it all need to be changed????