4.0 to 3.7 V6 swap

[TARA-fied1]

Hey all, I am new here but not new to Mustangs. I couldn't find an actual swap thread for the 3.7 Cyclone replacing the 4.0 SOHC so I thought I'd document my project here. Back story, the 07 4.0 auto was originally my wife's car. We bought it used but it was only a year or two old and in great shape. I have a rowdy big block 67 and a 93 GT I drag race, She wanted a tame daily driver and "told" me to leave her car alone. Anyway, long story short I couldn't leave it alone. I lowered it, put 07 Shelby wheels on it, GT500 rear bumper and Pypes dual exhaust. Stuff like that. Fast forward to last year. It started running bad and giving error code for random misfire. Ultimately it was the harmonic balancer that broke at crank, took out the timing chain drive sprocket and broke a few valves, poked holes in the pistons, etc. etc. So decision was made to buy her a different car. I would take over the 07. My current daily is a Lightning and gets 14-16 mpg and runs 93 octane so I wanted to make the 07 my daily but a 4.0 was not going to do. I found a 2012 V6 6 speed car that was wrecked but drivable for $1300 so I bought it. The swap should be a challenge but a fun driver with decent power and mpg. I may need some help along the way with some questions. Thanks for looking

 

[TARA-fied1]

a few pics of the 4.0 damage removing the auto trans, wiring, AC, PS, etc.

 

[TARA-fied1]

more pics of the "stuff" I have removed so far...

 

[TARA-fied1]

The Doner car, 2012 V6 six speed

 

[TARA-fied1]

pressure washed the engine bay today. Then I positioned the two cars to make the swap easier.

 

[TARA-fied1]

I beleive I am going to have to change every wire, module, etc. so the 2012 stuff doesn't realize it's in a 2007 body...

 

[AHaze]

I beleive I am going to have to change every wire, module, etc. so the 2012 stuff doesn't realize it's in a 2007

I've always thought this was the best approach when swapping to a different engine that was available in the same chassis. It may be more work initially but should greatly simplify troubleshooting of future problems.

 

[Juice]

I beleive I am going to have to change every wire, module, etc. so the 2012 stuff doesn't realize it's in a 2007 body...
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So you are really doing a body swap on a 12 then.

 

[Dino Dino Bambino]

So you are really doing a body swap on a 12 then.

He's gutted the '07 and is using the '12 as a donor car. That said, I wonder how easy or difficult it would be to do the reverse and graft body panels from the '07 to the '12 instead. Unless the frame rails are mangled, the rest is a case of cut and either weld or bolt on.

 

[Juice]

He's gutted the '07 and is using the '12 as a donor car. That said, I wonder how easy or difficult it would be to do the reverse and graft body panels from the '07 to the '12 instead. Unless the frame rails are mangled, the rest is a case of cut and either weld or bolt on.

Yes, I understand what he is doing.
My point is, if.you are swapping all harnesses and computers, thats a shit ton more work than just an engine swap. Essentially, he will have a complete 12, in the 05-09 body. So it is IMO, a body swap.

 

[TARA-fied1]

yeah I guess it is a body swap. The 12 frame rails might be okay. The car drives pretty straight and everything works. I have a "trunk ajar" for obvious reasons (no trunk lid!) and the tire pressure warning but I believe it just has junk yard roller tires and wheels on it with no sensors.
It is a lot of work. but my 07 is paid for and body and paint are in great shape. It has less than 100K miles on it. I will swap the 8.8 rear and bigger brakes, epas and probably the interior into the 07. I got the 12 for $1300 but has a salvage title. My wife preferred the auto, but I like to shift so the manual trans was a must when looking for a doner. I wanted a 3 valve 4.6 GT doner but the 2012 3.7 has about the same HP stock and gets 30+ mpg. It might not be worth the effort to some but I have already replaced the 07 with another car for my wife so I can take my time. It's challenge and a learning experience though!!!

 

[TARA-fied1]

these are the pics from the interweb ad

 

[TARA-fied1]

Still trying to figure out how to get all the wiring out of the car without cutting anything. The BJB on the 07 is able to be "unplugged" while the 2012 doesn't. I need to swap all the HVAC stuff as well. I think I can unplug the doors, I am hoping there is no "smart" tech in the doors. I do understand the SJB has to match the VIN so best I can tell the instrument cluster, PCM, SJB and key all have to be linked together. My 07 doesn't have ABS or side airbags so I will have those warning lights lit. the 2012 drivers seat has some damage and is dirty (more so than my 07 seats anyway). I may later hunt down some nicer 10-14 seats so I can plug them in. I am switching all the suspension so I might go ahead and swap the ABS stuff as well...

 

[Andrey Sidorov]

This is amazing, rare case swap that probably nobody have done before, plenty of coyotes to 05-09 s197s but never saw this probably because of the low cost of cyclone powered cars that makes it no financial sense to do a swap, plus better interior in general, but that makes it so much better and more special, subbed to thread

 

[redfirepearlgt]

According to the 2005 prints side airbags were available on the 05-09, there is a "Resistor Cap" shown used on page 46-4 of the supplemental restraint system in the Ford electrical drawings for the 2005 labeled "without side airbags". It is located on the drivers side airbag wiring harness under the seat and is labeled C3108 (C3109 pass side). It should be a 2 pin connector with a shorting plug looking thing clipped into it according to the Ford wiring prints for the 2005. There is a second one on the passenger side labeled connector C3109. To verify the connectors C3108/C3109 the wires are color coded as follows: Pin1 - White/Light Blue; pin2 - Red. C3109 pin1 - White/Yellow; pin2 - Brown/Yellow.

The wire codes assumes your year color codes are the same as the 2005. In some cases I have learned that they change though 05-09 models.

If you can find these, pull them and verify they are both the same resistance and then use that value to jumper across the unused pins on the newer harness you may be able to resolve the airbag light (and it will work correctly) being on all the time. Just a theory based on prints but thought I would chime in.

reference section 46-4 in the Ford 2005 Wiring diagram shop manual.

 

[TARA-fied1]

redfirepearlgt,
awesome thanks for the input! That could make things much easier. I will dig into this. I was gonna buy a wiring manual for the 12, might go ahead and get the 07 also.

 

[TARA-fied1]

This is amazing, rare case swap that probably nobody have done before, plenty of coyotes to 05-09 s197s but never saw this probably because of the low cost of cyclone powered cars that makes it no financial sense to do a swap, plus better interior in general, but that makes it so much better and more special, subbed to thread

I figured my 07 is worth about $2K with a blown engine. The junkyard 4.0's are relatively cheap (under a $1,000) so this isn't the best financial move but I couldn't let the little 07 just die! The 12 doner was $1,300. I'll have a ton of labor and some misc. parts but overall not a huge amount more than going back with a 4.0 and I get the 12 interior, well as much as I want anyway, and the 12 brakes, suspension and 3.7/6 speed/8.8 drivetrain, etc.

 

[TARA-fied1]

More and more gutted, and I found some funding...

 

[TARA-fied1]

I should shampoo the carpet while it's out!

 

[redfirepearlgt]

redfirepearlgt,
awesome thanks for the input! That could make things much easier. I will dig into this. I was gonna buy a wiring manual for the 12, might go ahead and get the 07 also.

i've got the 2005 prints and main shop manual on paper. Glad to shoot you page photos if you need anything in that regard. Just curious why you didn't look into a salvage S550 ecoboost swap. Not an S550 fan aside from the improved engines. They look great in S197's. LOL!

BTW I think I can see the 2 pin plug in that first photo in reply #18.