My gf's sister has a 98 or 99 Expedition w/ a 4.6l motor. It blew up on me the other day when I was taking it to Georgia. It just lost all power and whatnot. Would a 5.4 motor be a direct replacement? What about a 4.6l from a car? I've found them both on ebay for somewhat cheap prices, and they are a lot cheaper than fixing this one or buying a new one. I don't know what tranny it has, although it is a 4x4 and has the electronic o/d on the shifter. Thanks, Andrew

i'm pretty sure the lower end of the car motor would work. just replace its upper end with what came of the expedition. i would also make sure that the car block had all the sensors yours has, like crank or cam sensors.

as for the 5.4 i think the transmissions are different. and you would also need the computer and wiring harness for the 5.4.

The transmission will bolt to the 5.4, along with the v10. They all share the same bolt pattern. The 5.4 would probably be a pretty easy swap if you have the computer.

Anytime you rip a motor out your gonna have to have a computer or some kind of programmer that will allow you to reset all of configurations - if you just drop in the 5.4 (not a bad choice if you ask me) your speedometer will not work nor and I don't know whether the odometer will work either, but these harnesses and reconfiguration programs are not hard to come by. Your might want to make sure that they have the same electrical inputs because otherwise your gonna have to buy a converter or do some fancy modifications that far surpass my automotive knowledge.
Hope that was some what informational.

A 5.4 from the same year will have all the same connections. It'll even run on the 4.6 computer, but not optimally. The speedo and odo will work. The difference between a 4.6 and a 5.4 of the same year is about the same as a 302 and 351w.

if you just drop in the 5.4 (not a bad choice if you ask me) your speedometer will not work nor and I don't know whether the odometer will work either.


The '97-'98's had cable driven speedo/odo/trip meter, so it shouldn't matter. '99's and up were electronic.

But yes, it would be much easier if you got the complete wiring harness from the doner truck. However, there are people/companies out there that can go through your stock 4.6L wiring harness and make it work. One guy converted a 5.4L wiring harness and computer to work with a V10 he swapped in....

The '97-'98's had cable driven speedo/odo/trip meter, so it shouldn't matter. '99's and up were electronic.


No that is incorrect, all Expeditions use VSS signal for the speedometer.

8No that is incorrect, all Expeditions use VSS signal for the speedometer.

The 97 expeditions had a VSS sensor in the tailshaft of the BW4406 t-case. 98 and newer got their readings from the ABS sensor in the rear axle housing . I researched the piss pout of this when i swapped out my BW4404 AWD case in my mountaineer to a manual shift 4406 case.

The trannys are all the same. 4r70w. its just the rear axles that were different between the 4.6 and 5.4 in the expeditions.