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Loud engine noise above 35mph

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by GenZ Driver, Aug 9, 2020.

  1. GenZ Driver

    GenZ Driver New Member

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    Hello all!

    My Gen 2 '08 Prius of 101k miles makes an uncomfortably constant loud noise whenever I drive above 30-35mph. The faster I go, the louder it gets. Around the 50mph mark I have to shout to speak to anyone else in the car. The best way I can describe it (the 10 second video was too large to attach) is like it maintains a high rpm humming sound.

    Generally, we try keep it in good shape. I change the engine oil at regular intervals, I replaced the old timing belt a few months back, and we had the brakes changed earlier this year.

    I've taken a look at the exhaust and catalytic converter, nothing seems out of the ordinary. Somebody mentioned it could be the water pump but honestly I have no clue. I'm planning to the car to the garage next week but I'm open to all suggestions- if its something I can fix myself, I'm more than happy to do so!

    Many thanks, folks!
     
    #1 GenZ Driver, Aug 9, 2020
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Have you changed or checked the engine oil level lately?

    Does the noise change when turning or cornering?
     
    #2 SFO, Aug 9, 2020
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  3. edthefox5

    edthefox5 Senior Member

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    Timing belt? It uses a chain but I guess your referring to the water pump belt that’s good it was time.

    Why brakes at so low of mileage?

    The engine and drive train on this car is very quiet so you have a big issue.

    You sure the car wasn’t stolen?

    Go on YouTube and look up Prius inspection.
    It will show you the dance to Put the engine in inspection mode where it will run constantly till shut off.
    Pat attention to the exhaust system. Car should be very quiet really

    Or the hybrid battery is shot and you have all kinds of alarms on the dash and you have to floor it everywhere because it’s in limp mode.
     
    #3 edthefox5, Aug 9, 2020
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  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Hmm... I've not seen any version of the Prius that actually used a timing belt.

    Failed wheel bearings can make loud noises with the pattern/circumstances you describe. If it were an exhaust leak, the car would be quiet during the moments when operating electrically.
     
    #4 Leadfoot J. McCoalroller, Aug 9, 2020
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  5. GenZ Driver

    GenZ Driver New Member

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    I'm not due for another oil change until next month, and the oil level is fine atm.

    Nope, the noise remains consistent when turning.

    The brakes were worn a fair bit, braking distance wasn't particularly safe. My dad's one of those aggressive drivers so I'm sure he had something to do with it...

    Dash is clear, no alarms and whistles flashing up.

    I'll be sure to look up the prius inspection, thanks!

    I might have meant drive/serpentine belt? I'm new to car maintenance so I haven't got the terminology down yet.

    Ahh I didn't think about the wheel bearings, thanks!
     
    #5 GenZ Driver, Aug 10, 2020
    Last edited by a moderator: Aug 10, 2020
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