Odd sound coming from rear of truck when off/parked

I let my dog out last night around midnight and heard a faint humming sound coming from the rear of my 2013 Tacoma Off-road. It sounded almost like a pump or maybe even a fan. At first i almost mistaken the sound for a neighbors noisy AC unit. I crouched down and looked into the rear wheel well and it sounded like it was coming from under the bed (and got louder the more I crammed my ear into the wheel well).

Crazy part is the truck had been parked for at least 7 hours at this point.

Any ideas? The truck is barely a month old.

Thanks

 

I learn something new here every day!

Thanks

 

Terrorists

 

I walked out in the garage a month or so ago and the same sound was coming from underneath the FR-S. Sounded like my neighbors air compressor at first but then I realized it was coming from the car. I was about to freak out because it sounded like the fuel pump was running and the car was turned off. A quick check of the interwebs led me to the answer posted above. One item of note. I don't know if it does it on our trucks but on the FR-S as soon as you open the door the pump stops.

 

Awesome, thanks for the reply. Nothing like having a mental freakout in the middle of the night.

 

Lol.. no doubt. When we had 2 house payments we had to adjust our priorities and we ended up with 2, 06 models. I still remember to this day pulling out of the lot and I was waiting on a line of cars and the engine just died. I was like??? WTF???? I just bought this POS and the engine just fuckin died. Then I thought... maybe it's supposed to do that (didn't do it in the test drive mind you). So I gave it some gas and off it went like it was supposed to. And yeah... They make all kinds of strange sounds.

 

It's breathing.

 

I read on a toyota nation post that it is a fuel system pressure test. The sound is the fuel pump. Occurs 5hrs after parking vehicle. Same system on all newer Toyotas.

 

Holy crap I love TW. Just had this happen to me last night. Glad to hear it's normal.

 

Yep, normal. When I'm camping up in the mountains it has on more than one occasion caused my dogs to freak in the middle of the night.

 

Awesome, I love this site. Everything is covered here. I went to the garage to transfer the laundry (I was promised a late night treat) for doing it. Then I heard this weird noise. I came straight here and BAMB got it answered. I will now claim my treat.