New noise like a roar or drone at higher speeds

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Kpeeling, Nov 1, 2015.

  1. Kpeeling

    Kpeeling Junior Member

    Joined:
    Oct 8, 2013
    15
    3
    0
    Location:
    South Central PA
    Vehicle:
    2013 Prius
    Model:
    Three Touring
    I'm no mechanic and I don't know a lot about my Prius so I hope someone mechanical can help. I have a 2007 Prius (now has 220K + miles) I bought used about 2 years ago with 150K miles. I finally got used to the car sounds so this is something new, or rather it's becoming louder and enough for me to question it. The car is still quiet at low speeds but this sounds like something related to how fast the car is rolling, not the engine acceleration. It doesn't sound like it's coming from the wheels. It's a low roar like sound, not high pitched and it sounds like it's coming from under the middle to front of the car as if related to perhaps the drive train. If I am up to 40-50 mph and just rolling (foot off the gas) down a long hill, the sound is there. It gets louder the faster I go. Could it be a transmission sound? I've always had manuals so this is my first automatic transmission car. Is there a fluid level I should have checked or maintenance I should have had done by now? I hope someone has heard this before and knows what it is.
    Thanks in advance.
     
  2. WilDavis

    WilDavis Senior Member

    Joined:
    Feb 4, 2014
    2,424
    2,073
    49
    Location:
    Top RH Corner of RH Coast on L side of The Pond
    Vehicle:
    2009 Prius
    Model:
    II
    Tyres? As they wear, their sound might change. Check for uneven wear patterns (fairly easy to see) which might be caused by bad alignment. hope this helps - Wil
     
  3. Kpeeling

    Kpeeling Junior Member

    Joined:
    Oct 8, 2013
    15
    3
    0
    Location:
    South Central PA
    Vehicle:
    2013 Prius
    Model:
    Three Touring
    Thanks for responding. I only wish it is something that simple. Last fall I put on 4 new tires and have had them rotated. No abnormal wear is obvious. I plan to have my mechanic listen this week to see if he can ID the noise. I'm leery about having a dealer listen since they always recommend tons of work for tons of dollars.
     
  4. m.wynn

    m.wynn Senior Member

    Joined:
    Oct 24, 2013
    674
    1,185
    0
    Location:
    Queensbury, NY
    Vehicle:
    2014 Prius
    Model:
    Three
    Although it could be a transaxle issue surfacing, at your car's age and mileage I'd suspect one or both front wheel bearings. My daughter's '07 lost the passenger side at 140k and the driver side at 150. Diagnosing the passenger side was tricky as it was nearly impossible to tell which side the noise was coming from. When the driver's side went I just assumed it was not the passenger side again and this was correct.

    If you "'slalom" the car from side to side, does it make the noise louder with regard to which direction you're swerving? Popular opinion among mechanics is that the bad bearing will be opposite the direction which makes the noise louder. In my case it was just the opposite, swerving to the right was loudest and it was the passenger side bearing that was bad. I was able to make the call by having my wife drive so I could compare the noise I was hearing from both sides of the passenger compartment. Raising the front end and spinning the wheels in neutral was no help and there was no "play" in either wheel when lifted off the ground. It's really a bit of a crap shoot to diagnose. Knowing what I know now, and at your mileage, I'd just do them both.

    The Timken HA590064 is likely the OEM Koyo bearing and can be had for $101 on Amazon if you're DIY. This is the bearing I used. Toyota dealer will want $700-$1000 to do both. Perhaps a good independent mechanic will meet in the middle but I'd require the Toyota factory part or the shown Timken.

     
    #4 m.wynn, Nov 1, 2015
    Last edited: Nov 1, 2015
    Kpeeling and Dino33ca like this.
  5. dpeverhart

    dpeverhart Member

    Joined:
    Jul 24, 2012
    125
    21
    0
    Vehicle:
    2007 Prius
    Model:
    I
    A good mechanic should be able to properly diagnose this. My guess is a front wheel bearing, or both fronts. I've seen these go at around 180k. If it's a northern car they can go much earlier. We've used Moog bearings with good results. They run around $100 at Advance Auto Parts after using online discount codes. Labor shouldn't be too bad, maybe an hour or two.
     
    Kpeeling likes this.
  6. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    4,898
    3,194
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    Wheel bearing. The noise is transmitted through the drivetrain and can sound like it is coming from elsewhere.
     
    Kpeeling likes this.
  7. Kpeeling

    Kpeeling Junior Member

    Joined:
    Oct 8, 2013
    15
    3
    0
    Location:
    South Central PA
    Vehicle:
    2013 Prius
    Model:
    Three Touring
    Seems to be a consensus here so I will ask my mechanic to check it out. I'll take it out for a drive today and check the slalom suggestion. Thanks!
     
  8. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,177
    1,232
    1
    Location:
    Trumbull, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    Kpeeling likes this.
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    9,070
    6,627
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    How's your musical ear? Do you have a sense for what pitch the drone is at a given speed (or can you use a cheap tuner app on your phone for that)?

    The first time I had a wheel bearing go, I was concerned about the possibility it could be the transaxle, until I worked out that the pitch wasn't related to any whole-number multiple of the transaxle MG2 rpms, and that relaxed me about the major worry so I could just look more calmly for the real problem.

    A few years later when I had a front bearing go, I heard a characteristic pitch from it too, different from the rear (but I have a Gen 1, where front at rear bearings are quite different styles; the exact details may be different for your Gen 2, because it uses the same type of bearing front and rear, though the sizes might be different).

    -Chap
     
    Kpeeling likes this.
  10. Kpeeling

    Kpeeling Junior Member

    Joined:
    Oct 8, 2013
    15
    3
    0
    Location:
    South Central PA
    Vehicle:
    2013 Prius
    Model:
    Three Touring
    Never have drained and refilled the ATF. Actually, that's why I am fearing the sound as transmission related. I'm headed out to test the slalom idea now.
    Update: Drove on curves. I'm now pretty sure we are talking wheel bearings. It is much louder on right curves and much quieter on left ones. There's no mistaking the difference. This forum is awesome! Off to the mechanic as soon as I can get an appointment to verify my suspicion. Thanks to everyone.
     
    #10 Kpeeling, Nov 2, 2015
    Last edited: Nov 2, 2015
  11. cyclopathic

    cyclopathic Senior Member

    Joined:
    Apr 15, 2011
    3,281
    536
    0
    Location:
    2014 Prius c
    Vehicle:
    2010 Prius
    Model:
    II
    Yes tires and wheel bearings are first to check.
     
    Kpeeling likes this.
  12. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,177
    1,232
    1
    Location:
    Trumbull, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    While having the wheel bearing fixed drain and refill the ATF with Toyota type WS ATF (~$10 per qt - you need 4 and 2 crush rings). My Toyota dealer charges $100, but it is a straight forward DIY (see: ATF fluid changes ARE Required. | Page 27 | PriusChat). Capture a few ounces of the used ATF in a clean Poly bottle so you can send it in to R&G Laboratories, Inc. - Home for analysis (~$25) and report the results on PC.

    JeffD
     
    #12 jdenenberg, Nov 3, 2015
    Last edited: Nov 3, 2015
    Kpeeling likes this.
  13. Graham Salvage

    Graham Salvage New Member

    Joined:
    Nov 5, 2016
    1
    0
    0
    Location:
    manchester
    Vehicle:
    2008 Prius
    Model:
    N/A
    Please can you let me know how it goes? - I have the same problem....(not tires...)
     
  14. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    4,898
    3,194
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    FYI, sad to say but the OP hasn't been back to give us any verification since posting this over a year ago.
     
Loading...