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

Very Loud Engine Sound

Discussion in 'Gen 2 Prius Main Forum' started by Metrolens, Apr 18, 2019.

  1. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    Hi all, I started my 2005 Gen 2 today, and when the ICE kicked in, out of the blue there was a horrible sound - like a car without a muffler, or a car modded to sound extremely loud. Actually some would probably say this is a wonderful sound - like a muscle car on steroids. But I digress.

    The sound originates from under the hood, driver's side near the ICE, not from the muffler in the rear.

    My OBDII + Torque showed no error codes. There is no Main't Required light.

    Yesterday the car was driving perfectly, and there was no pothole or anything which would have obviously jarred something loose. My layman's guess is a hose or something popped off, and now we are hearing the raw sound of the ICE?

    Thoughts? Obviously I have to take this in to be repaired, but first and foremost, is the car DANGEROUS to drive even a few miles to the mechanic?
     
    #1 Metrolens, Apr 18, 2019
    landspeed, Abiy Desta and Data Daedalus like this.
  2. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,088
    5,805
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    someone cut out your catalytic converter? Take a look under the car and see if the exhaust pipe is missing between the engine and muffler. Seems to be happening a lot.

    Or donut gasket blew out between exhaust manifold and pipe
     
    #2 TMR-JWAP, Apr 18, 2019
    Data Daedalus likes this.
  3. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    The car has been parked on the street in LA; I imagine cutting out the cat converter would make a bunch of noise and/or take some time, and require getting underneath the car. Interesting theory, but seems unlikely?

    If it's the donut gasket, is that dangerous to drive, or just super loud?
     
    #3 Metrolens, Apr 18, 2019
  4. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,088
    5,805
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Really....you should read some of the recent posts here about this exact scenario...come and gone in just 2 minutes.....manymany posts about it

    As for the donut gasket, no danger, just loud and a bit of carbon monoxide.

    Assuming it's the exhaust and not something else.

    Maybe the O2 sensor or AF ratio sensor fell off the exhaust?
     
    #4 TMR-JWAP, Apr 18, 2019
  5. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    What would it look like if the cat converter had been stolen?
     
    #5 Metrolens, Apr 18, 2019
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,686
    48,942
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    a big empty space between the exhaust pipe and the muffler. LA and london are hotspots. they steal them for the precious metals.
     
    #6 bisco, Apr 18, 2019
    Data Daedalus likes this.
  7. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    Would there be wires cut, hanging down?
     
    #7 Metrolens, Apr 18, 2019
    Data Daedalus likes this.
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,686
    48,942
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    no, just the gap in the exhaust. they use a cutter wheel, make two cuts in the 2" pipe and walk away with it.
    jforpics, see the 'stolen catalytic converter' threads here.

    if you can't see under there, drive it to a local mech or muffler shop
     
    #8 bisco, Apr 18, 2019
  9. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    In this youtube video, a news report from yesterday, at 45 seconds they show the undercarriage of a Gen2. You can see the wires to the right. Is the car in this video missing its cat converter? Is the space where the cat converter should be the shiny corrugated metal section at 45 secs? I'm not sure what the undercarraige would look like with/without the converter. Thx.
     
    #9 Metrolens, Apr 18, 2019
    Data Daedalus likes this.
  10. Metrolens

    Metrolens Member

    Joined:
    Sep 3, 2012
    190
    33
    0
    Vehicle:
    2005 Prius
    Model:
    II
    (Actually you don't even need to watch the video - the YouTube still image shows exactly what I describe at the 45 second mark.)
     
    #10 Metrolens, Apr 18, 2019
    Data Daedalus likes this.
  11. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    6,786
    6,444
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    Depending on where the cuts are made they will also be taking one of your oxygen sensors. Doing so would necessitate cutting the wires connecting the sensor to the engine ECU. This is common and likely in Prius converter thefts.
     
    #11 Leadfoot J. McCoalroller, Apr 18, 2019
    Last edited: Apr 18, 2019
    Data Daedalus likes this.
  12. Data Daedalus

    Data Daedalus Senior Member

    Joined:
    Jul 6, 2013
    1,022
    1,182
    0
    Location:
    Wembley, London
    Vehicle:
    2008 Prius
    Model:
    II
    You’ve just had your catalytic converter stolen. The Prius 2 is such an over engineered vehicle, no other mechanical failure fits this profile.

    You’ll need a new cat installed, and will need to see about getting protection installed on it too.....or they’ll be back for it.

    Happened to me in London November 2018.
    Over 1,000 Prii have been attacked in London alone.
    The local law enforcement consider the matter a victimless crime, so have allowed the thieves to run riot in London over the last 10 months, much to the dismay of us Prius owners there.

    Hope you can get your Prius fixed.


    iPhone 6s +
     
    #12 Data Daedalus, Apr 19, 2019
  13. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Really bad news is its a carb state so they will not accept an aftermarket cheapo cat. Must be the factory cat. $$$$$$$.

    Which is why they steal it.
     
    #13 edthefox5, Apr 19, 2019
    Data Daedalus likes this.
  14. oil_burner

    oil_burner Active Member

    Joined:
    Feb 26, 2017
    249
    126
    0
    Location:
    Canada
    Vehicle:
    2006 Prius
    Just about every muffler repair shop offers free inspection. Drive it there they will tell you what's wrong in 15 minutes
     
    #14 oil_burner, Apr 19, 2019
  15. Tharbeard

    Tharbeard New Member

    Joined:
    Oct 30, 2020
    1
    0
    0
    Location:
    Portland, OR
    Vehicle:
    2008 Prius
    Model:
    N/A
    So, I got in my car and it sounds like I'm surrounded by motorcycles. I'm assuming I'm in the same boat and the OP: either stolen catalytic converter or a blown donut gasket?
     
    #15 Tharbeard, Oct 30, 2020
  16. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    stolen cat. sucks. cant let the car out of your sight. Just look under the car if you see dangling wires.....

    Go on youtube and search

    Prius Stolen

    Lots of info about it.
     
    #16 edthefox5, Oct 30, 2020
    Data Daedalus likes this.
  17. gui

    gui New Member

    Joined:
    Jun 6, 2023
    7
    1
    0
    Location:
    California
    Vehicle:
    2006 Prius
    Model:
    I
    there is a good chance that it's a stolen cat
     
    #17 gui, Jun 6, 2023
  18. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,483
    3,763
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    That was four years ago.
     
    #18 dolj, Jun 7, 2023
  19. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,257
    15,060
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Ok, there's a good chance it was a stolen cat.
     
    #19 ChapmanF, Jun 7, 2023
(You must log in or sign up to post here.)