View Full Version : 3.6l to 4.6l swap , is it possible ?

11-25-12, 04:30 AM
Just purchased a 05 cadillac sts
It's been a crazy ordeal !
Basically it's a 3.6l and I'm going to have to replace the motor
My friend has a wrecked 07 sts with 4.6l
I was wondering if it is possible to swap the motor


11-25-12, 06:45 AM
You'd be far easier off usin your car to fix his.

11-25-12, 08:02 AM
Yup, take the good parts from the 05 and put them on the 07.

11-25-12, 11:00 AM
Also with both being totaled out the 07 is worth more based on year and vin unless the 05 has a ton more options but as salvage it won't really matter much in the end.

The 07 has a 6spd tranny and the 05 has a 5spd

11-25-12, 11:22 AM
In addition to having to swap the forward lamp harness and engine harness across with the engine, the main body wiring harness (and if I recall, the instrument panel harness) are also different between the two engine options. Of course anything is possible, but this could turn out to be a lot of work. It would be far easier to buy an engine from someone like Schram Auto.

12-03-12, 04:56 PM
Well do you think it is possible with a 4.6l from an 05 sts
Or am I just stuck with swapping it with another v6

12-03-12, 07:53 PM
If you have an '05 with a bad 3.6, you probably need an '05 3.6. An '08 3.6 would likely be a real challenge; older less so.

12-03-12, 08:41 PM
You're much further ahead staying with a 3.6L. Anything is possible, and I love to pull things off that GM says can't be done, but the reality is the level of work and financial commitment just isn't worth it.

I'm not really familiar with the 3.6, other than it is direct injection in the later model years. This may well create some issues for you, although I believe less so than a 3.6 to 4.6L swap.

12-03-12, 09:11 PM
Like stated previously, just fix the wrecked V8 STS with parts from the V6 STS with the blown motor...much easier and far less expensive.

12-04-12, 01:06 PM
I can't purchase the shell of the car.
It's his grandma old car , so he was just letting me have the motor for free
Just thought it be easier to replace with v8
Found a good deal on a totaled 05 with 4.6. Motor is $750 and trans $450

12-04-12, 01:35 PM
Definitely not easier to swap a 4.6 into a car with a 3.6....you'd need all of the wiring harness, PCM, TCM, EBTCM, etc, everything! Not your average 350 swap with these cars, too many electronics in the way.