Help needed: Booming Resonating Noise in Cabin at idle and low rpms

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by [email protected], Oct 13, 2014.

  1. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    256
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    If that means seeing an experienced Prius mechanic.......then you probably should.
    Worn out bearings can have some strange symptoms in the beginning.
    At least one person asked about the oil level and I don't remember a reply on that.
     
  2. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
    I'm the mechanic that instead the cat-back exhaust. When I came back in I relooked (again) the back part of the exhaust to ensure there is not contact and the hangars were intact. All hangars are good and the exhaust hangs freely..

    I may run it and move the exhaust to see if that changes the idle drone.
     
  3. northwichita

    Joined:
    Sep 24, 2006
    481
    100
    29
    Location:
    Wichita KS
    Vehicle:
    2004 Prius
    Cat-back exhaust means what exactly.
     
    #23 northwichita, Oct 13, 2014
    Last edited: Oct 22, 2014
  4. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
    Sorry--original exhaust until the production break after cat and resonator. Only replaced a portion of rusted out exhaust and muffler--sounded perfect for the 8 months. As matter of fact, a rusted out muffler doesn't sound as bad as this....
     
  5. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,159
    727
    0
    Location:
    sterling, VA
    Vehicle:
    2006 Prius
    Model:
    II
    motor mount could be bad but not completely broken so that the engine doesn't move very far when you put it in and out of gear. never done a prius mount but some mounts will collapsed and cause the noise op described. usually its louder inside than out.
     
  6. GrumpyCabbie

    GrumpyCabbie Senior Member

    Joined:
    Dec 14, 2009
    6,723
    2,117
    45
    Location:
    North Yorkshire, UK
    Vehicle:
    2010 Prius
    Model:
    III
    Aha, now we're getting somewhere. :rolleyes: So you've replaced the back/rear section of the exhaust?

    Not sure how or why the muffler was rusted out considering they're made of high quality stainless steel. But it depends where in the World you are I guess. Even in the UK where salt is used on our roads the stainless steel exhausts on a Prius last 10-15 years. Older cars using steel ones rot in a couple of years.

    And is this replacement a genuine Toyota part or a pattern part or even a non standard or performance part?
     
  7. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
    I can;t recall where the original exhaust failed but it was a clear failure and gave the pri more vocal umph. The replacement was certainly not a "performance muffler", it was OEM from Toyota.
     
  8. AzWxGuy

    AzWxGuy Weather Guy

    Joined:
    May 22, 2011
    819
    400
    0
    Location:
    Tucson, AZ
    Vehicle:
    2021 Prius
    Model:
    Limited
    I'm going to vote for exhaust heat shield noise. You'll have to get the car up in the air, make ready, and with engine running modulate the accelerator until the noise is produced.
     
    GrumpyCabbie likes this.
  9. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
  10. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    737
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    I think mine has same noise. But just not as bad. Sound is clearly resonating booming and modulated by load and rpm. First you could only hear it sometimes if it had run long time without engine spinning and then engine started on steep hill. Then sound only lasted for about one second. Now in similar situation sound is one second on half second off one second on (about not actually timed). But now sound can also be heard when engine is charging battery but its temperature is less than about 20c or 68F. I think that sound comes from exhaust manifold heat shield or something else in that area.


    I would really appreciate info from you since it already starts to be below freezing and not very nice to work outside.
     
  11. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
    Sorry for the delay in my response, been busy working. Good news is problem solved!

    Apparently a vibration damper [looks like a cast iron bump stop (2" diameter) of sorts] came free and got wedged between the torsion/roll restrictor and the car. When we got it on the lift apparently the flexed enough and it came from. Boom, grabbed it and the car drove like new. I still don't know where it came but I'm happy for the time being.
     
    Mendel Leisk likes this.
  12. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    94,611
    42,889
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
  13. Easy Rider 2

    Easy Rider 2 Senior Member

    Joined:
    Aug 5, 2014
    1,584
    256
    0
    Location:
    Ocala, FL
    Vehicle:
    2013 Prius c
    Model:
    Three
    Let's see.....parts are falling off my car......yet I am happy. :eek:

    I think you should find out where the part came from and why it came off.
    It might be important......or not......but you need to know, IMHO.
     
  14. belbert@metrocast.net

    [email protected] Junior Member

    Joined:
    Feb 4, 2007
    17
    2
    0
  15. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    94,611
    42,889
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    ignorance is bliss.:p
     
  16. Mendel Leisk

    Mendel Leisk Sand Pounder

    Joined:
    Oct 17, 2010
    45,440
    32,437
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Can you post a picture of the part that dropped out?
     
  17. northwichita

    Joined:
    Sep 24, 2006
    481
    100
    29
    Location:
    Wichita KS
    Vehicle:
    2004 Prius
    Glad you found and fixed the noise problem, the lower engine mount , middle of car at the bottom, has that damper.
    Here is an ebay photo
    http://thumbs4.ebaystatic.com/d/l225/m/mBF1-TagBF9X-HONiDncUHA.jpg
    Looks like a good paper weight, I'll try to remove mine the next time I change oil, I don't think the car needs the extra damper weights Toyota puts on the car.
     
    #37 northwichita, Oct 25, 2014
    Last edited: Oct 25, 2014
  18. alekska

    alekska Active Member

    Joined:
    Feb 14, 2010
    435
    135
    0
    Location:
    Atl
    Vehicle:
    2005 Prius
    Deleted.
     
    #38 alekska, Oct 25, 2014
    Last edited: Oct 25, 2014
  19. Ian Paul

    Ian Paul Junior Member

    Joined:
    May 31, 2015
    4
    1
    0
    Location:
    UK
    Vehicle:
    2005 Prius
    Model:
    N/A
    mine fell off as well, not sure when but I found it a couple of weeks ago, it was making a sort of squeaking noise coincident with forward or reverse torque on the engine, took ages to find.
    It was very rusty, I think the car has spent most of its life in Glasgow, lots of salt on the roads I guess.
     
  20. GrumpyCabbie

    GrumpyCabbie Senior Member

    Joined:
    Dec 14, 2009
    6,723
    2,117
    45
    Location:
    North Yorkshire, UK
    Vehicle:
    2010 Prius
    Model:
    III
    Or the pot holed roads and hitting them speed bumps a little to quickly? ;)
     
Loading...