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2006 Engine Noise - buzzing, especially loud on highway

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by smorgen, Apr 17, 2012.

  1. smorgen

    smorgen New Member

    Joined:
    Apr 17, 2012
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    Location:
    Cleveland, Ohio
    Vehicle:
    2006 Prius
    Model:
    N/A
    For the past few months I've been hearing a loud fan-like buzzing noise coming from the passenger side of the front of the car. I don't know that much about cars, but it almost sounds like the engine is racing or something is spinning too fast. It has gotten increasingly worse, and seems especially loud at high speeds on the highway.

    It is not the heating/cooling fan - the noise is present when the heating/cooling system is turned off.

    I have noticed a few things, the noise is not present when the electric engine is on (regardless of speed) but is present at speeds greater than 30 mph when the gas engine is on and gets louder as the car gets faster.

    The car just turned over 100,000 miles today!

    Any help or advice you could give would be awesome, thanks!
     
  2. northwichita

    Joined:
    Sep 24, 2006
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    Location:
    Wichita KS
    Vehicle:
    2004 Prius
    I would check the water pump and the tensioner first. Take off the belt and turn by hand, they both should turn very smoothly if good.
    See this link for access to the parts, also probably a good time to change the belt while you are there.
    http://priuschat.com/forums/knowledge-base-articles-discussion/87166-belt-change-how-photos.html

    The right front wheel bearing could also be suspect, does the noise change when you turn the steering wheel back and forth? That is one simple test for a bad wheel bearing. In this case, there would be more sound when turning left, with a bad wheel bearing on the right. A wheel bearing is much tougher to fix, but just to try to isolate the problem, does the sound vary more with the speed of the car, or the speed of the engine ?
     
  3. genboy

    genboy New Member

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    Vehicle:
    2009 Prius
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    Hi! What was the resolution, Champ?
     
  4. genboy

    genboy New Member

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    Vehicle:
    2009 Prius
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    Hi northwichita! I just noticed the same problem with my 2009.

    No change with turning the steering wheel. The sound is very much like heading out to your favorite fishing hole with Dad, in his Lund, with his 40 hp Evinrude running steady. The roar becomes evident about 30 mph, and is a very steady outboard or small airplane engine type roar, which I'm pretty certain varies with road speed, based on my tests. So it goes gradually up in pitch (not a *lot* though) but not necessarily in volume as the car goes faster, but not if I, say, rev the engine. It's not tire/road noise.

    I'm not really equipped at the moment to remove any belts, sorry...but I do appreciate your help.
     
  5. smorgen

    smorgen New Member

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    Apr 17, 2012
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    Location:
    Cleveland, Ohio
    Vehicle:
    2006 Prius
    Model:
    N/A
    In my case it was the bearings that were bad, we had them replaced for the passenger side front and haven't had any issues since. The driver side seems to be fine so far. Good luck!
     
  6. genboy

    genboy New Member

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    Vehicle:
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    Same here. Drivers side wheel bearing. Toyota dealership says about $600 to replace. Local mechanic says $250. Maybe less. :)