I have the same noise. How come it sounds when unlocking too? If it were the pump, this wouldn't make sense. I think it's the passenger door actuator.

sure its not the throttlebodies doing their self check?

Why would it do a self check with the car on and you hitting the "unlock" button?

I know on a lot of cars the fuel pump begins to engage when the doors are unlocked. High performance cars do this more frequently. My brother's M6 and R8 V10 both do this, it's very obvious. I doubt it's a door actuator, they don't make whining noises like that - it's got to be the fuel pump.

I think your Z has caught the case of the 335's. good luck with the fuel pump

I'm sorry but I'm having a hard time believing this. What would be the logic behind having the fuel pump "engage" (whatever that means) every time I hit the unlock button on the door?

Not trying to be an ***, just playing devil's advocate.

The fuel pump engages because it's getting ready for you to start the car. This is extremely common on cars, these days. Like I said, high-performance cars do this where it's evident and you can hear it clearly. I have a video of my brother's R8 starting up, I'm standing a good 10-15 feet away and you can hear the fuel pump turn on as it whines during its 2-second engagement, right before he fires the car up.

Not all cars employ this, because some still rely on gravity fed fuel if the design makes it possible. But if a car requires a fuel pump, the fuel pump will frequently engage when the car is unlocked, so that you have an immediate start of the motor and keep wear on the starter to a minimum.

I dunno, the logic just seems flawed to me. It sounds when the doors unlock when I turn OFF the car. Why would the fuel pump engage when turning the car off?

it's not that it's engaging, it's shutting down after you turn the car off. also, when you unlock the car and open the door, some cars prime the fuel system by running the pump for a few seconds. this is normal. definitely sounds like your fuel pump. may not be anything wrong with it

Yeah 370fan you sound confused. The sound of it engaging and disengaging would be the exact same. And it would occur prior to start and after shut off.

i hear that noise from my car too
it may sound weard but it seems like some of nissan car with push start engine feature makes that noise somehow,, altima and rogue makes same noise!!!:eek:

yeah, I am confused, as the sound happens when I unlock the car even with the car ON...

thanks for trying to clear it up, I'm just not completely sold because I feel that sometimes it makes the noise when there is no sense for the pump to prime or turn off.

You may be talking about a different sound then.

It is most likely the fuel pump. This sound is also heard in my 11 Z and my wifes 10 Maxima. My money is on the fuel pump theory.

Resurrecting an old thread here, but thought I might help...

11K miles on my 2011. For the past couple of months, I've also had this occasional 1-second "brrrpt" whiney noise from the right-rear when I shutdown the car. Seems like it's become more frequent as the weather cools off. Before really investigating, I felt it was the fuel pump or evap system doing some kind of purge too. But I get the door lock/unlock thing too sometimes, so that doesn't make sense. While detailing my Z last weekend, I figured it out.

It's the fuel-filler door locking mechanism.

If you get this noise, open your fuel-filler door (just the door, not the cap), then cycle through lock & unlock with your key fob. Car doesn't need to be running. Observe the fuel-filler door locking mechanism. It's plainly obvious on mine that it's this mechanism when retracting/unlocking that's making the noise. If I grab hold of the latch, I can feel it vibrate. I can even change the pitch of the noise if I put pressure on the plastic hook part (making the solenoid struggle or whatever it is).

It also makes sense why it would show up in other Nissan's, as I'd bet they have a locking fuel door too that probably uses the same part.

I tried fiddling with it a little bit. I hit it with some silicone lube & tried to work it down the cylinder, but it didn't seem to help. I was thinking of hitting it with a little 3-in-1 oil, but haven't yet.

I plan on having the dealership take a look at it on the next oil change, but since I know it's not the fuel pump and just this latching mechanism, I'm far less concerned about it. Though I suppose if it failed completely, it could refuse to unlock the fuel door, which would kind of suck.

Hope this helps someone.