High Pitched Whining Noise After I turn Prius Off and Turn it On

Discussion in 'Gen 2 Prius Technical Discussion' started by Austin Middleton, Apr 5, 2013.

  1. Austin Middleton

    Austin Middleton New Member

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    I know this noise is the Thermos Pump and it operates when I turn the car on and off. Question - do you guys experience this too? Or is it failing - also a really annoying noise, but I'll put up with it as long as nothing's breaking.
     
    #1 Austin Middleton, Apr 5, 2013
  2. jdenenberg

    jdenenberg EE Professor

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    It only runs for a short time, I just ignore it. The thermos is more trouble than it is worth as the pump and the control valve have had maintenance issues. Toyota no longer puts one in the Gen3 or later models.

    JeffD
     
    #2 jdenenberg, Apr 5, 2013
  3. Austin Middleton

    Austin Middleton New Member

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    Is it a mileage or emissions thing? Would it be a big deal if I just unplugged it? Would that cause the check engine light to come on?
     
    #3 Austin Middleton, Apr 5, 2013
  4. jdenenberg

    jdenenberg EE Professor

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    Yep, there are sensors that will report a problem to an ECU if you try to disable the pump.

    JeffD
     
    #4 jdenenberg, Apr 5, 2013
  5. KK6PD

    KK6PD _ . _ . / _ _ . _

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    I think I would be more worried if I did not hear the pump running after I shut the ca down!
     
    #5 KK6PD, Apr 5, 2013
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