fan or pump type noise when parked

I've had the 2017 for 3 years and never heard this. Drove earlier today, it's been parked 6 hours and a fairly quiet sound is coming from under the box maybe near the gas tank, seems louder on the left side. I can best describe it as an electronic fan or pump type noise. What would be running under there hours after it's parked and cold?

 

a friend just told me the fuel pump runs every so often to keep the fuel mixed, his does it too... problem solved! Funny I've never heard it before.

 

Probably emissions, not fuel pump.

 

Its the evap system. Totally normal

 

Totally normal, it's an EVAP test as mentioned in the Owners Manual.

 

It's just regulating the pressure in the gas tank. Nothing to worry about
The first time I heard it, I was a little worried too. But with a little research, there's nothing to be worried about!

 

First time we heard this on our old chevy cobalt (bought new got rid of it a few years ago) sounded like someone beating on the gas tank lol. We called it the munchkin in the trunk when someone else asked us wth it was.

I haven't even noticed it on my taco yet but I'll take that kind of noise of the noise our old cobalt made anyway. Always messed with me if drove it when I worked 2nd shift. Was tired as hell and suddenly knock knock knock in the back of the car.

 

thank you! I figured something like that but it is a bit alarming when first heard

 

Hahaha! I just had this experience the other night for the first time and just had the fuel pump recall done. I was worried they jacked something up. Good to know.