1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Transmission noise

Discussion in 'Gen 2 Prius Main Forum' started by Alnilam, Aug 12, 2006.

  1. Alnilam

    Alnilam The One in the Middle

    Joined:
    Jun 8, 2006
    760
    10
    0
    Location:
    Carlsbad, CA
    Vehicle:
    2006 Prius
    I know I'm leaving myself open to ridicule by saying this, but a couple of times I've found myself moving with the freeway traffic at high speeds, especially in the HOV lanes where I don't want to be the bottleneck. I've noticed that at about 83 mph, if I add some gas, the engine/transmission makes a sound similar to what I used to associate with a slipping clutch. You know, the engine speeds up but the car doesn't seem to be getting all the torque. It does speed up, but this noise bothers me. Is something slipping, besides my brain?
     
    #1 Alnilam, Aug 12, 2006
  2. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,039
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    No. Prius engine RPMs are not directly related to road speed, and the engine needs to rev up to provide the necessary power through the electric generators and motors. For the same reason the engine will roar when going up a long grade at speed. It's normal.
     
    #2 richard schumacher, Aug 12, 2006
  3. Alnilam

    Alnilam The One in the Middle

    Joined:
    Jun 8, 2006
    760
    10
    0
    Location:
    Carlsbad, CA
    Vehicle:
    2006 Prius
    <div class='quotetop'>QUOTE(richard schumacher @ Aug 12 2006, 09:18 AM) [snapback]302133[/snapback]</div>
    Thanks. That makes sense. In all other cars the ICE is just used to power the wheels. I forgot that in this one it also has electrical duties. It's a pretty smart transmission that can maintain a smooth ride while the engine is jumping around in speed.
     
    #3 Alnilam, Aug 12, 2006
  4. hobbit

    hobbit Senior Member

    Joined:
    Mar 23, 2005
    4,089
    468
    0
    Location:
    Bahstahn
    Vehicle:
    2004 Prius
    Model:
    N/A
    The fact that you're running the engine power output up that high
    to maintain 83 mph should, um, tell you something.
    .
    _H*
     
    #4 hobbit, Aug 12, 2006
  5. Alnilam

    Alnilam The One in the Middle

    Joined:
    Jun 8, 2006
    760
    10
    0
    Location:
    Carlsbad, CA
    Vehicle:
    2006 Prius
    <div class='quotetop'>QUOTE(hobbit @ Aug 12 2006, 10:56 AM) [snapback]302172[/snapback]</div>
    You got me...... :(
     
    #5 Alnilam, Aug 12, 2006
  6. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,074
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    There is absolutely nothing to slip. The noise is just the ICE making more power.

    Tom
     
    #6 qbee42, Aug 12, 2006
  7. IsrAmeriPrius

    IsrAmeriPrius Progressive Member

    Joined:
    May 27, 2004
    4,333
    7
    0
    Location:
    Southern California
    Vehicle:
    2005 Prius
    <div class='quotetop'>QUOTE(Alnilam @ Aug 12 2006, 10:09 AM) [snapback]302157[/snapback]</div>
    The Prius does not have a transmission in the traditional sense. It has a planetary gear power splitting device.
     
    #7 IsrAmeriPrius, Aug 12, 2006
  8. jeromep

    jeromep Member

    Joined:
    Dec 8, 2004
    827
    2
    0
    Location:
    Eastern Washington State
    Vehicle:
    2005 Prius
    Model:
    N/A
    <div class='quotetop'>QUOTE(Alnilam @ Aug 12 2006, 01:53 PM) [snapback]302247[/snapback]</div>
    Yeah, me too Bob, I'm not sure just exactly what hobbit meant, but I'm fairly certain that it is either related to greater fuel consumption at high speeds or it is related to the engine RPMs going someplace.

    That is the important part to consider with the Prius, engine RPM always has to go someplace. It is either being directed to the wheels, or to the MG or, in most instances, to both. In that sense, we can also agree that there is no slippage, because the engine is physically connected to gearing which is in turn connected to electrical devices or the final drive.
     
    #8 jeromep, Aug 16, 2006
(You must log in or sign up to post here.)