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Hi,

Noob question:

can I upgrade the 3.7L on a Jeep commander to the more powerful 4.7L?
is it possible? will it affects other components of the vehicle?

Thanks!
 

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Hi,

Noob question:

can I upgrade the 3.7L on a Jeep commander to the more powerful 4.7L?
is it possible? will it affects other components of the vehicle?

Thanks!
With the refinements and electronics of today's vehicles, engine swaps are just NOT that easy. Your best chance would be too trade your vehicle in on 4.7L equipped Commander.

You'll need the PCM for the engine and its wire harness.

3.7L have the NAG1/W5A580 Trans

4.7L have the 545RFE Transmission

Since they are electronically controlled, you could run into all sorts of extraordinarily expensive to solve problems trying to mate the W5A580 to 4.7L. Maybe the electronics would adjust themselves, maybe NOT, I don't think anyone knows. NOT the least of the problems of this solution, the W5A580 does NOT have torque and impulse capacity to handle a 4.7L V8 with the weight of a Commander. It probably would work, but the trans would wear out much sooner than others and be far more likely to suffer problems and fail.

If you swap entire engine trans setups, the transfer case has got to go with it. And most 3.7L are QT1 and most 4.7L are QT2, meaning you'll have to upgrade the 4X4 systems as well. That is additional electronics modules as well, even wiring harness's.

If you have a Junkyard donor car, it may be economically feasible, but still expensive.

There are threads about someone that has swapped in a 6.1L Hemi in replace of a 5.7L Hemi, that would be easier than a 3.7L to 4.7L, since the engines are much closer in design*. The poster may be able to offer you some advice and an idea of the cost and complexity of doing such a thing, my guess a swap from 3.7L to 4.7L would be more expensive and complicated.

*Yes, I know they made a lot of block and other changes to the 6.1L from the 5.7L, but as far as the electronics go, its the same motor with more displacement. Well, more stroke and different cam profiles, which complicates the spark tables even more, fuel tables can adjust themselves (at least I think so).
 
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