Hey Guys, my VQ25HR engine of my Nissan Skyline 250GT 2010 (Infiniti G25) 7 speed AT sedan cocked up. Instead of replacing it with the same engine, I was considering upgrading to a VQ37VHR motor from a V36 sedan of the same year. Is it as simple as plug-and-play or should I look to make adjustments in the Engine bay for it to work. Much appreciated.

 

great question and even better idea with the upgrade. While I have not seen any personally, I dont know of anything that would cause any issues as it should be a direct swap. What country are you from as you have indicated the 250gt skyline, that might be an issue?

Wiring harnesses should all be the same and I wonder if the ECU is the same?

 

I would honestly be surprised if the wiring and ECU are the same. Body harnesses should all be identical but the engine harness and ECU for sure will have differences. Other than that I think it should all just bolt up.... the hard part will be the electronics.

 

Go to discountinfiniti.com and compare part numbers as a start. Since a Skyline is not USDM, that might not be definitive but it should be a start.

 

try to get an engine from 2012 or newer as the older ones may be susceptible to oil gallery gasket failure

 

I've done a few Nissan upgrade swaps before. Haven't done this chassis, but there are a few things I can share:

All hard-point mounts will definitely be the same, should not need any custom fab.

Harnessing will route same way.

Most body sensors will be compatible.

There is a strong chance the 25 engine will have different sensors/actuators than the 37 engine. Might be a different kind of VVTi, different sensor layout, hard to say. I would definitely acquire the 37 engine to ECU harness at least.

I recall some Infiniti's/Nissans would have either hydraulic or electric power steering, depending on engine or options chosen. This would also affect your ECU calibrations and compatibility. Be sure the donor 37 and 25 car have same kind of power steering system.

You should plan on doing a 37 ECU also. On Nissans I have done before, the NATS system and the smart key from the ECU's donor car also needs to be obtained to avoid having to ask a dealer to reprograms your keyless start system. My last swap required the donor car ECU, keys and the transponder, even the transponder was coded to the ECU.

If it were me, I wouldn't hesitate to swap a 25 to a 37. Should be totally doable, and we may start seeing these occur more frequently as these cars get older.

 

Thanks for the elaborate reply. I'll surely seriously consider this option. My inclination is to get the motor plus its ECU

 

Thanks for this. I'll definitely start off from here...

 

I am based in Kenya, the car is a JDM car....

 

Update: in the recent light we are seeing a lot of success for the dual TB VQ. Many folks have discovered that the 3.7 block can be swapped right on over to a VQ35HR thus making a "37HR". These swaps seem to be the saving grace for folks who are down to take an engine apart for cheap power.

I suspect that the VQ25 has the ability to do this as we'll since the outside of the engine is practically similar to a 35HR. If this is truly the case then you would be able to block swap your VQ25. In theory you'd be making a "37HR".

Whether this setup demands tuning to run I know it'd be a waste to do all of this work and not tune it.

I make kits for VHR swaps and it gets pretty expensive. An HR would be about 1/2 - 3/4 of the price.

 

G25x owner here.

I have done a tat of research before. As mentioned previously, you will need an ecu that doesn’t have the electric steering (no G37s) unless you’re gonna swap the steering as well.

If I remember correctly, the transmissions are not quite the same, they have a different part number. Maybe they aren’t rated for as much power? You’d have to look into that as well.

Side note: The VQ25HR is quirky in terms of timeline. V36 body but some how it’s more similar to a VQ35DE, still had the pain in the *** dipstick for some reason.

 

How did this work out? Currently doing mine. Any tips?

 

Lets keep it factual here guys.

Every V36 chassis came with hydraulic primary powersteering that utilizes an electronic solenoid at the top of the rack for speed sensitivity. Power steering will not be any different.

As I stated before the easiest will be a 37 block swap.
The other way will be to do a full electronic swap along with engine and trans swap.

 

how did this work out for you? What was the process? And what all did you have to change?

 

how did this work out for you? What was the process? And what all did you have to change?