Engine scraping sound

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by David Scott Dallas, May 27, 2022.

  1. David Scott Dallas

    David Scott Dallas Junior Member

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    I have a strange engine sound. 2011 Prius with 114k. Unknown maintenance history. Being sold by Carmax. When the engine kicks on there is a scraping sound like something is dragging even when the car is not moving. Happens when I drive slowly up to about 40 or 50 then don’t hear it anymore. If I accelerate under electric power only there is no sound. As soon as the engine kicks on there it is. The sound doesn’t change with speed. Sounds the same sitting still as it does going 50. Any ideas?
     
  2. rjparker

    rjparker Tu Humilde Sirviente

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    Do a good video of the engine that captures the sound. Usually noises "go away" after 50 mph because of road noise masking them out.
     
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  3. David Scott Dallas

    David Scott Dallas Junior Member

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    It doesn’t seem like road noise is masking it. It’s very clear at 40to 45. Gone at 50.
     
  4. ChapmanF

    ChapmanF Senior Member

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    Does it change with engine speed?

    You are able to "race" the engine a little while sitting in Park. It is computer controlled (throttle by wire), so there's no direct connection, but the computer is programmed to say "hmm, driver is pushing the go pedal while we're parked, ok, I'll play along and increase the RPMs a little". :))

    If the sound doesn't have some quality that's proportional to the engine speed, then it may well be a loose buzzy heat shield. Those can sound a little like scraping.
     
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  5. David Scott Dallas

    David Scott Dallas Junior Member

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    Lol. Never mind. It was the heat shield loose around the cat converter
     
  6. David Scott Dallas

    David Scott Dallas Junior Member

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    Yeah you nailed it!
     
  7. David Scott Dallas

    David Scott Dallas Junior Member

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    By the way should I take that off of the car? Do I really need it?
     
  8. CR94

    CR94 Senior Member

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    Toyota spent the money to put it there for a reason. Can you devise a way to secure it so it doesn't rattle?
     
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  9. rjparker

    rjparker Tu Humilde Sirviente

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    Usually a cat heat shield is designed to protect other parts of the vehicle from excessive catalytic converter heat. The problems prevented could be melted wires, extremely hot floorboards, overheated electronics or outright fires.
     
  10. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

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    Yeah "should I rip this part off?" is usually not a good idea. Well maybe except for those plastic wheel covers...
     
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