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Knocking Noises in Coolant Transfer Pump?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gadgetdad, Dec 1, 2008.

  1. Gadgetdad

    Gadgetdad New Member

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    Location:
    Modesto, California
    Vehicle:
    2010 Prius
    Model:
    IV
    Hi everybody! Sorry I have been away from PC for awhile, but a new noise has developed in the coolant transfer process on my 07. I couldn't find an answer in the "Search" process so can anybody help?

    Upon shut-down the howls and grinds (ah, sweet music to the Prius owner's ears) come from the coolant transfer pump as usual, but about 25 seconds later a "knock, knock, knock, knock" noise comes from somewhere else in the system. The knocks are fast and louder than the usual grunts. The knocking/tapping sound repeat some 20 seconds later, and then a third time about 20 seconds later. I'm due for a 40K oil change and may let the dealer do it this time if they can help with the new noise, but it would help if my PC friends could help with a diagnosis. Any ideas great collective mind of PriusChatters?:cool:

    Lee
     
    #1 Gadgetdad, Dec 1, 2008
  2. edthefox5

    edthefox5 Senior Member

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    Clearwater, Florida
    Vehicle:
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    Two
    New one. Have someone shut the ICE of while your under the hood ready to listen and find out exactly where the knocking is coming from. Knocking is not good.
    Report back.
     
    #2 edthefox5, Dec 2, 2008
  3. danjan101

    danjan101 Junior Member

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    just had this develop on my 2005. Did you ever find out the problem?
     
    #3 danjan101, Jan 12, 2022
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Have the hood open when you turn the car off, then listen for where the noise is coming from. I might guess that it could be from the "3 way" coolant control valve.

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Jan 13, 2022
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