1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Whirling sound coming from the back

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by carbon6, Jun 18, 2010.

  1. carbon6

    carbon6 Junior Member

    Joined:
    Oct 25, 2009
    9
    0
    0
    Location:
    Beaveron, OR
    Vehicle:
    2009 Prius
    Model:
    N/A
    My 2009 Prius was parked in the garage for over 4 hours when I noticed it was making a weird noise. It was a continuous low buzzing, whirlling noise coming from the rear of the car. It was most pronounced when I stuck my head near the rear wheel wheel. I started the car, letting the ICE kick in, then turned it off, and the noise went away. In any of my "old school" vehicles, I'd say it was the fuel pump stuck on, but with the Prius, I don't know. Maybe a fan in the battery compartment?? Why would it be stuck on after 4 hours of sitting? Any Ideas?

    Thanks,

    Mike
     
  2. halpos4

    halpos4 "Taxi"!

    Joined:
    Aug 13, 2008
    377
    24
    5
    Location:
    Ireland
    Vehicle:
    2006 Prius
    There is a fan that keeps the battery pack cool,the vent at the rear passenger seat is where the air is drawn in,i've never experienced the noise that fan makes,temperatures here in Ireland are never that high even in summer.
     
  3. Politburo

    Politburo Active Member

    Joined:
    Feb 15, 2009
    971
    208
    0
    Vehicle:
    2009 Prius
    There is some kind of fuel system check that it does after being off for a couple hours. I don't think the battery fan will run unless the car is on, but I could be mistaken.
     
  4. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,075
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    That was the fuel system leak test. It pressurizes the fuels system and checks to see how long it can retain the pressure. The test starts several hours after you power down, on the assumption that the car will probably not be used for awhile. When you started your Prius you canceled the leak test.

    Tom
     
    1 person likes this.
  5. carbon6

    carbon6 Junior Member

    Joined:
    Oct 25, 2009
    9
    0
    0
    Location:
    Beaveron, OR
    Vehicle:
    2009 Prius
    Model:
    N/A
    Thanks all for your input. I was at the dealer yesterday and got the run around about having to wait for their "Certified Prius Mechanic" take a look at it. All I wanted was an explanation of what I was hearing. The service writer said he thought it was the coolant pump that you hear when you shut down. LOL.

    Thanks again,

    Mike