I have a 1998 F150 4&4 ext cab with a 4.6 liter engine. Will a 5.4 engine bolt onto my tranny and do I have to change the computer and wiring harness?

 

all you will really need is to have a new tune made.

 

Ahhhh, the search button - what a great resource !!!!

https://www.f150online.com/forums/sh...d.php?t=278779

https://www.f150online.com/forums/sh...d.php?t=250001

JMC is the man when it comes to this type of info !!!

If you want to read more, open the Search window, search for swap, put JMC in the user name to search under and select Engines as the target forum.

That is how I retrieved the above links - there were plenty more to read....

BTW - Welcome to F150online !!!

 

There is more to than just bolting them up. Here is a list.

Regards

JMC

Notes for 4.6 to 5.4 swap

Exhaust: The collectors on the exhaust manifolds are set at different angles and locations. The 4.6 exhaust will not bolt up to 5.4 manifold.

Ignition: All 5.4 engines use Cop ignition. 97-99 4.6 engines use coil packs. It is easier to wire your 5.4 using the harness from the 4.6 and the 4.6 ignition coil packs. If you use the 4.6 Coil pack ignition you will have to fab a bracket for the driver side coil pack.

Engine harness: The IAC harness must be relocated to the rear of the throttle body elbow. The oil sender wire on the 4.6 is too short so it must be extended. All 97-00 4.6 engines use some sort of intake manifold runner control valve. Remove it from the 4.6 and plug it into the 4.6 harness and bolt it to the engine some where out of the way. Note you can get a tune to remove its function and eliminate it all together. All 97-98 4.6 engines use an engine coolant temp sensor. Some use 2. None of the 99+ 5.4s use any. You will have to tap the intake manifold crossover pipe to fit the sensor. Some 4.6 engines (97-8) have two sensors.

Transmissions: the 4.6 and 5.4 have the same bellhousing bolt pattern. That means that all the transmissions will bolt up. All the 5.4 engines have 8 bolt crankshafts. Some 4.6 engines (ROMEO ENGINE) have 6 bolt cranks. You will need the flex plate from the 5.4.
Manual transmissions: If you don’t have an 8 bolt flywheel a flywheel from a 1997-8 4.6 Windsor engine will work. As it has 8 bolts it will bolt right up to the 5.4 crank. Remove the flex plate spacer and install a pilot bearing from a 4.6.

Tuning: It is best to have a custom tune done to accommodate the extra displacement of the 5.4.
You should be able to use the 4.6 MAF as any competent tuner can adjust for it. It is always best to discuss this with your tuner.

Misc: Both engines use the same engine mounts and their location on the block are also the same so your old ones will fit. Unbolt and place aside the AC and PS. You need to remove the intake manifold for the engine to come out. Yes there are 3 bolts on the starter.

Knock Sensor:
The 97-98 99 4.6 uses a 2 wire knock sensor. The 97-98 5.4 has 3 wires of which one is a ground. Both have a Yellow /red wire to pin 57 on PCM.

1997-98-99-2000-01 Yellow/red to 57 on PCM 4.6 Same for 5.4.
97-98 Pin 91 feeds power for 4.6 and other components. Same for 5.4
1999- 2000-01 Pin 32 for power. Same fore 5.4
2002+ Cannot confirm.

 

Hey JMC great info.

I have a 2001 f-150 4.6l romeo engine that is dead. I have found a low mile 2000 5.4l bi-fuel, will this fit? I think the answer is yes.. if so will I need a new ECM? I hear I need to pull the cab to get the engine out is that true? Also (sorry) last question. You mentioned that the exhausts are a different angles, how have folks adapted that?

thanks


JMM

 

You mentioned that the exhausts are a different angles, how have folks adapted that?
___________


You can either get a ford Y pipe for a 5.4 for your truck, or you can tow it to a good muffler shop and have the pipes custom made... that would be my choice.

 

Cheapest solution is to have a muffler shop bend up some pipe.

JMC

 

thanks guys... Vendors says I'll need a new ECM for the Bi Fuel 5.4 instaed of using my 4.6 ECM. Do you agree? I take it the engine should fit with the mods required as JMC outlined in his post?

Thanks so much


JMM

 

I would think you would need a bi fuel ecm only if you plan on running e85. a regular 5.4 ecm would work just fine I would think

 

Hi I have just completed this swap, including removing the body, as access with a 4x4 is abysmal. The mechanical stuff was easy, but 3 Ford garages and multiple private shops are completely stymied at the "re-flash" suggestion. It seems the processor communicates that it is for a 4.6 engine I tried a different computer(5.4) with even worse results.(I'm using 4.6 ignition, and that really wierds out the computer.) I'm really close, but have drivability issues (too lean ?0 thanks for more info.

 

Ford techs are oblivious to the aftermarket support, they do not and most will not acknowledge it.
u also need tuning to help compensate for the CID of the swap.
not sure why u removed body on a 4x4, i did the swap with a L intake, lt headers.