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04 Prius Engine Noise

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Priusguy63, Nov 24, 2015.

  1. Priusguy63

    Priusguy63 New Member

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    My Prius has been making this exact same noise for over two years now. Should I be concerned? What is making this noise?


    Thanks!
     
  2. JC91006

    JC91006 Senior Member

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    if it's the pump or pulley, replace them
     
  3. kutcht1

    kutcht1 Member

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    That does sound like a bad bearing, either in a pulley or the water pump. Replace the worn part.
    TomK
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    To determine what is the problem, you would remove the serpentine drive belt and rotate the engine coolant pump and the tensioner pulley by hand. Replace any part which does not rotate smoothly. If the coolant pump bearing is seeping coolant, that is another reason to replace the coolant pump.

    The serpentine drive belt should be inspected for cracks on the interior surface and replaced as necessary.
     
  5. Priusguy63

    Priusguy63 New Member

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    Bad coolant pump makes sense now that you say it. Did an oil change last week and noticed fresh fluid on the front right axle. I've never messed with the serpentine belt before. Is there a side view diagram I could use?
     
  6. Dino33ca

    Dino33ca Member

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    How many miles? You don't want to take a chance on not replacing an inexpensive serpentine belt. I've heard of posters damaging their engines from overheating due to a failed belt. It's rare but it does happen.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You can find an exploded parts diagram in the factory repair manual, techinfo.toyota.com

    I wrote the following post about how to replace the engine coolant pump here:
    How to replace engine coolant pump and thermostat | PriusChat
     
  8. Priusguy63

    Priusguy63 New Member

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    It has 260,000 miles.

    Planning on replacing coolant pump, serpentine belt, idle pulley and thermostat (not sure if I need this but its cheap). It's been neglected for quite some time. Is there anything else I should have the mechanic look at or replace while doing these things considering the miles it has?

    Appreciate the responses!
     
  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I suggest you have the front struts, rear shocks, brake system, and exhaust system inspected and parts replaced as needed. Drain and replace the inverter coolant and the transaxle ATF. Replace the brake fluid.
     
  10. Priusguy63

    Priusguy63 New Member

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    Thanks Patrick!