My 2013 Gen 3 (93k miles) hasn’t been driven much these past two weeks. I just made a short trip early yesterday morning and parked it. About 5 hours after I parked it, I walked out to the garage to a slight humming noise. Further inspection led me to a motor/whirring noise underneath on the inside of the passenger rear wheel. Sounds almost like a fuel pump but constant and a bit louder. Close to the fuel tank. This is NOT the brake booster/actuator noise that year hear when opening the driver door for the first time in awhile. It’s similar sounding but a lot quieter and in the area described above. Any insight of what this could be? I’ve never heard this before. While searching for the sound, I noticed it speeding up & slowing down and it took about 5 minutes to locate it. I’m guessing it was going on for a few hours and just randomly shut off when I was feeling around underneath.
Likely normal; there’s a self-test the gas tank vapour collection system does, hours after shut down.
It wasn't going for a few hours, and it didn't shut off randomly. That's the leak-detection pump for the evaporative emissions system, and it runs in steps B, C, D, and E of the self test, which starts about five hours after you park the car (sometimes delayed a bit longer, in extreme temperatures). Step C is the step whose time is variable, so the pump will be on for roughly between seven minutes and 22 minutes, depending on how long step C takes.
Funny Toyota likes that 5-hour mark I have to look up and see what that's about It's the same thing for the generation twos coolant heat storage tank pump 5 hours after shutdown it should come on sample the water and so on just like this thing is sampling the Evap or whatever it's doing
