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Rattling noise Comming from Under dash acceleration issue

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Greg Kaiser, Aug 19, 2012.

  1. Greg Kaiser

    Greg Kaiser Junior Member

    Joined:
    Aug 19, 2012
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    Location:
    Santan Valley Arizona
    Vehicle:
    2008 Prius
    Model:
    II
    Hi

    New to the Forum. There is allot of good info on this site. Thanks
    Soon I will replace my transaxle fluid, inverter coolant, PCV valve and maybe the drive
    Belt. Oh and clean throttle Body. I have a manual. I have a 2008 Gen II. It has 69,500 miles.

    I notice not always a rattle coming from under the dash (left drivers) Like a baby rattle or rain stick
    when the brakes are applied but not always. Sound like high voltage maybe?

    Also when getting on a freeway ramp up hill and excellerating allot I seem to get stuck in what
    seems to be 3rd gear space for too long. The RPM rate seems too high for the speed Is this a real issue or just a Priusism. I thought changing the Transaxle oil might help? No error codes

    Thanks

    Greg
     
    #1 Greg Kaiser, Aug 19, 2012
  2. gmcneil05

    gmcneil05 Member

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    Avon Park, Florida
    Vehicle:
    2012 Prius
    Model:
    Five
    I don't know what the rattle is but the being stuck in third gear is normal. Fluid doesn't have anything to do with it. The trans in a Prius is more like a manual because the fluid just lubricates but it is not used to pump in a converter. It's all electronic so the computer keeps the revs at whatever is best for the current situation. It is high when accelerating but is only around 2,100 rpm at 70 which is what my 02 vette with a 6 spd runs at. Also if your battery is low at the time it will be higher then usual because most the torque comes from the electric motor.
     
    #2 gmcneil05, Aug 19, 2012
  3. northwichita

    northwichita .

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    I would speculate the rattle you hear is the brake actuator which is pressurizing the brake system. Mine started running excessively, had to change it, and now I don't hear anything but a click or two when the brake is depressed. Bleeding the brakes helped mine for several months, something to consider, but my clicking came back (up to 20 sec's at a time), so I changed it.
     
    #3 northwichita, Aug 19, 2012
  4. edthefox5

    edthefox5 Senior Member

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    Location:
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    Vehicle:
    2007 Prius
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    Two
    Yes its the brake vacuum pump (actuator).
    You can replicate that sound by just pressing on the brake pedal firmly 3 times with the car off. Is that the sound?
    Sounds just like a rattle snake.
    And the over reving is normal. Its just the engine and planetary gears doing there thing. Its not actually over reving it just sounds that way.
     
    #4 edthefox5, Aug 19, 2012
  5. Greg Kaiser

    Greg Kaiser Junior Member

    Joined:
    Aug 19, 2012
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    Location:
    Santan Valley Arizona
    Vehicle:
    2008 Prius
    Model:
    II
    Thanks for the replies
     
    #5 Greg Kaiser, Aug 21, 2012
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