Electrical winding noise when turned off?

[Big Blue Beasty]

Hi, I have a 2009 D40 STX, I noticed one night while sitting in the ute tray a sort of electrical winding noise (hard to accurately describe noise) that came on at regular intervals lasting for approx 20 seconds, seemed to come on approx every half hour or so and did so all night, the car was switched off unlocked and parked on a slight incline, sounded like it was coming from behind the back seat area. I've listened since and haven't noticed it making that noise since but I haven't spent all night sitting in the tray either. Any ideas what it could be?

 

[ARBNAV]

Could be fuel pump champ... Take it to nissan and they can pick it up on the computer if its a fault...

 

[KraftyPg]

Noises like this have come up a few times on this forum. Can't think of the specific threads but until someone who can think of them come along try doing an advanced search of the D40 section (think most of the threads have been in D40's) using words like noise, ignition off, or other such words. There is a few answers there somewhere.

 

[sevenmile7]

Mine does it as well. Try loosening off your fuel cap. If the breather is slightly blocked it makes that funny sound.

 

[Old.Tony]

If it's petrol it could be the fuel pump. Diesels have to drive the pump off the engine, so no revs = no pumping.

Inside the cabin it could be air flow control doors but they shouldn't keep at it unless something was wrong.

Underneath the car, the transfer case has electric motors in it - they should be idle though (unless there's a fault).

 

[Big Blue Beasty]

Cheers everyone, I'll suss it out a bit more, your answers have given me a couple of things to check out.

 

[JPMC]

I'll put money on it that it's the fuel tank vacuum/pressure relief valve. (Built into the fuel cap)

As the fuel changes temp the valve opens to equalize the pressure in the tank to stop it exploding or collapsing in on itself.