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brutal engine noise

Discussion in 'Gen 2 Prius Technical Discussion' started by rrmtinc, Sep 23, 2012.

  1. rrmtinc

    rrmtinc New Member

    Joined:
    Sep 23, 2012
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    Vehicle:
    2004 Prius
    Model:
    Four
    Our 04 Prius makes a really scary metallic noise at the top of the engine when it is engaged. All maintenance has been performed within 100 miles of the warning light. We are the original owners and the car has 160k miles. No pulleys are touching their surroundings. Make no mistake, this a LOUD noise that has been growing with time. No warning lights,,,oil level is fine,,,and no metal visible on the dipstick. Sound is originating at the top of the engine and is not a "knock". It is more of a metal on metal type of noise. Hopefully someone knows what is could be and not what I feel it is.
     
    #1 rrmtinc, Sep 23, 2012
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    at 160k it could be almost anything. are your mpg's changing? oh, welcome to p/c!
     
    #2 bisco, Sep 23, 2012
  3. xs650

    xs650 Senior Member

    Joined:
    Jul 2, 2010
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    Location:
    Northern California
    Vehicle:
    2010 Prius
    Model:
    II
    Try the easy things first.

    The GenII has a belt to drive accessories. Try removing the belt and running the engine for a few seconds to see if the noise goes away. Don't run it for more than a few seconds without the belt or your engine will overheat.

    If the noise goes away, check the idler pully for roughness when turned, noise or looseness. A lesser possibility is the water pump if the noise goes away when the belt is off.
     
    #3 xs650, Sep 23, 2012
  4. northwichita

    northwichita .

    Joined:
    Sep 24, 2006
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    Location:
    Wichita KS
    Vehicle:
    2004 Prius
    Still unknown?
    If not external to the engine (also my first guess) I would take off the valve cover and check as you say, the top of the engine.
     
    #4 northwichita, Sep 30, 2012
  5. HaroldW

    HaroldW Active Member

    Joined:
    Mar 17, 2012
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    Location:
    Grand Forks BC Canada
    Vehicle:
    2014 Prius
    Model:
    Three
    Yes, I would check the lifters and valve adjustment. :( H
     
    #5 HaroldW, Sep 30, 2012
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