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Persistent Fan Noise from Engine Bay

Discussion in 'Gen 2 Prius Technical Discussion' started by ingyaningya, Feb 12, 2018.

  1. ingyaningya

    ingyaningya Junior Member

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    Location:
    Miami
    Vehicle:
    2007 Prius
    Hello!

    I currently am in ownership of a 2007 Prius with 78,000 miles clocked on the odometer. My question is regarding a noise I’m sure we’re all familiar with as Prius owners. I’m talking about that fan-like noise which is reminiscent of the clattering of a 1960’s computer thinking away. It’s that loud fan noise we all hear at start up (when depressing the break),at idle, and at shut-down. One of those quirky hybrid noises.

    The best way I can describe it is a loud clattering noise originating from the engine bay that lasts a couple seconds. No big deal. But, my newly recognized issue is that while I’m driving, this noise will keep happening every 10 seconds — like clockwork. No matter how far the drive, every 10 seconds on the dot, this clattering fan noise will go on. Then off. Then on. Then off. It’s driving me mad!

    Same goes for when I have the transmission in P. While the car is sitting, it’ll still keep doing it. The car has always made this noise. But now it’s extreme noticeable in terms of its frequency.

    Does anyone know what this is? Or is this just one of the headaches that come with owning an aging hybrid? Please help! I can answer any questions regarding my car in order to help y’all help me get down to the bottom of this mystery.

    Thanks!!
     
    #1 ingyaningya, Feb 12, 2018
    Last edited: Feb 12, 2018
  2. edthefox5

    edthefox5 Senior Member

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    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
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    Two
    If your talking about the rattlesnake kind of noise that’s the brake vacuum acumulator. Like a sniksniksnik kind of noise. Brakes need vac to work normally comes from engine but engine does not run all the time so Prius uses electric pump,
    If your hearing that constantly run the brake abs unit has a leak. Pretty common. There was a TSB on it
    Not sure if it has run out.
    If abs unit has failed it will throw a master caution red icon on the dash and brakes will feel bad.
    Open the hood th pump is deep in th engine compartment down underneath the inverter the big silver cover on th right. Put the car in ready open the hood see if that’s the noise.
     
    #2 edthefox5, Feb 12, 2018
  3. ingyaningya

    ingyaningya Junior Member

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    Vehicle:
    2007 Prius
    Yes, I opened the hood with the car in ‘READY’ and the sound is indeed originating from under the inverter. So, if there is a leak, how long can I drive on it until something bad happens? At the moment, there is no master warning light or any other warning lights. Is this an expensive part to fix?
     
    #3 ingyaningya, Feb 12, 2018
  4. ingyaningya

    ingyaningya Junior Member

    Joined:
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    Location:
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    2007 Prius
    Also: I have a very long commute of over 100 miles per day, I want to make sure I’m not destroying my poor car lol
     
    #4 ingyaningya, Feb 12, 2018
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