# Swapping out V6 for V8 engine?



## lock_one_in (Feb 19, 2018)

Hello,

Hopefully the expertise of all the members here will help me....

I have a 2008 Nissan Pathfinder SE (V6 4.0L engine) and this past fall the engine blew (160K miles). Anyway, I have been looking for replacement engines and came across a 2008 Nissan V8 5.6L. My questions....

1. Can a Nissan V6 4.0L be swapped out for a Nissan V8 5.6L? I know V8 engines were an option in the Pathfinder but are there any major modifications that would need to be done for it to fit in my vehicle that came with the V6 4.0L standard? I am wondering if they used a different transmission to handle the torque and/or different engine mounts, additional supports, etc. Possibly bigger radiator for cooling capacity, different mounting to make room for the longer engine?

2. Anyone know a good place to source Nissan engines (new or remanufactured)?

Thanks for your time and answers guys, I appreciate any help!

Morgan


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## smj999smj (Jan 1, 2006)

Honestly, I really don't think it's worth the work and cost to swap the 4.0L-V6 to the 5.6L-V8. You're only gaining 44 HP and 100 ft/lbs of torque and losing about 4 MPG. You can make some upgrades to the VQ40DE to improve performance and not sacrifice the gas mileage. On my 2006 Pathfinder, I installed an XPS intake plenum spacer, aFe Momentum CAI system, Superchips tuner, Doug Thorley headers and mid-pipes and replaced the factory muffler with a Magnaflow 12580. It really woke the engine up, especially when using the 93 Octane tune, but even the 87 Octane performance tune is much better than stock. Honestly, the best bang for the buck was the Superchips tuner and the intake spacer; they were the only ones that felt like they improved performance significantly. 
The 4.0 and 5.6 use the same transmission, but the valve body "may" be different. The V8 Pathy uses the same radiator but has heavier duty front and rear axles. I would imagine you would probably need the engine harness and the ECM (you might be able to have your original ECM reprogrammed by a dealer). The exhaust system is different and the V8 has a larger front sway bar. I would think that with the V8 mounts, it would bolt in without an issue. The air intake system is different, as well. The V8 Pathy uses larger front brake rotors and calipers, but the steering knuckles are the same so the calipers and mounts, rotors and pads will all swap over; front brake hoses are the same. There is probably a couple of more differences that I can't think of off-hand. Keep in mind that engine swapping on a modern vehicle with a CAN system is a lot different than the old days before computer controls! All of the electronic modules communicate with each other so you need to do your homework to make sure you don't end up with a bunch of warning lights and triggered trouble codes when you get done. But, as I said earlier, I think your best option is to stick with the VQ40DE and do some mods to up the performance, if desired. BTW, you can also get more aggressive camshafts for the VQ40; it's not an easy job to swap them but you will have the engine out of the vehicle and it's not a bad idea to install a new timing set if the replacement engine is of the 2005-2010 vintage to prevent the possibility of the infamous timing chain "whine" that sometimes occurs on these engines when the upper timing chains cut into the tensioner faces.


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