Noise in left rear fender well

Over the last month I’ve went outside to check my garage and heard a noise. I thought it was my refrigerator running at first , but walked down and noticed it was coming from my truck. As I fit closer I noticed it coming from the left rear fender well. I’m curious if this is normal or if it’s a relay sticking for my fuel pump or what it might be. It’s been parked and turned off for a few hours by the time I’ve noticed it each time. If I start my truck and turn it back off it quits. Any ideas or anyone have this issue

 

It's the Evap system, perfectly normal.

 

Woke up in the middle of the forest on acid to this noise. Was scary as hell.

ETA, def EVAP

 

It happens 5 hours after you shut off your truck.

 

What is it? Vent?

 

It’s a system mandated by the regulators. A pump runs to check the integrity of the fuel system seals by drawing a vacuum on your tank.

 

Toyota started that system on the Tacoma starting with the 2005 model, amazing how many times the question has been asked over the past 15 years.

 

My wife’s Camry does the same thing. Once I was in the garage and both kicked in at about the same time. I had no idea what was going on.

 

That’s crazy I would’ve never guessed that. Thank you guys and God Bless.

 

They were communicating with each other, lol. I first heard my old truck do it back in 2008 in the middle of the night.

 

Welcome to TW, this is about the best place to learn about your truck, lots of good guys here.

 

I have no idea why this needs be so complicated.

 

Weird. Don't most mfg do that while engine running? Shut the vent valve and monitor pressure sensor for gross leaks etc?

 

I think almost all cars do this same thing now. They “come to life” in the garage. I don’t think Toyota is doing this to be good guys.

 

We’ve all been there. Welcome to TW.

 

Fair. Just never heard of adding complexity. I guess it's more controlled/ eliminates all the piping to the intake? Idk, I vaguely grasp what they're doing but not entirely

 

That intake piping is still there I believe. I’m not sure why this check needs to happen 5 hours later.

 

I think has to do with temperature.... running vs stationary (off)

 

Dude the last page on that PDF is POWERFUL for diag.

 

The “purge valve” is what goes to the intake. That’s how the vapours get burned I believe.