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Grinding sound when slowing down

Discussion in 'Model S: Driving Dynamics' started by AMPd, Oct 31, 2016.

  1. AMPd

    AMPd Active Member

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    My 2015 P90D has started making a grinding sound when slowing down.

    Around 25-20 mph it sounds like gears grinding

    Is this normal?
    Used to be quiet.
     
  2. azdryheat

    azdryheat Member

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    I just noticed this too. Had the radio off and windows down. Planning on recording it next week when I get back home. Does not sound normal to me. I will post a video of it when I can.
     
  3. sbtz

    sbtz Member

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    I'd ask if you have SAS, but your signature doesn't indicate that you do. Mine makes a whirring noise every time when slowing down to 25mph -- I always suspected that it was the SAS raising the car to "standard" height from low.
     
    • Informative x 1
  4. SmartElectric

    SmartElectric Active Member

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    Sounds like the car likes to go fast ... sorry, just kidding.

    Seriously tho, if you don't hear any noise during acceleration, but hear sound only on deceleration, then I've not read any accounts of such an issue. Obviously there are lots of accounts of sound during accel and decel, but that's not what you are reporting.
     
  5. AMPd

    AMPd Active Member

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    I do, it raises after 55 mph
    The sound will happen if I slow down from 45-50
     
  6. Drewflux

    Drewflux Member

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    @AMPd whats your regen set to? Im wondering if your brake rotors are glazed and making noise under braking.
     
  7. Chasedrgc1223

    Chasedrgc1223 Nearly Insane

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    Definitely would need to hear a recording to point us in the right direction.
     
  8. AMPd

    AMPd Active Member

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    Standard.
    I'm not using the brakes when this sound happens.

    I'll try to get that

    I might also pop into the service center and see if the tech has time to go on a ride with me. I'll report back on what he says
     
  9. Drewflux

    Drewflux Member

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    Hmmm thats an intresting concern. so you are slowing down in overun/ regen when the noise is occurring. im thinking a diff/ drive unit issue. i would try low regen or apply a very light throttle when the noise occurs to take the regen load off the diff to isolate. whats your tyre condition like. just wondering if you have one tyre better than the other, causing the side gears of the diff to bind.
     
    • Informative x 1
  10. AMPd

    AMPd Active Member

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    Just got new tires after hitting a pothole.
    Same issue, I will try setting the car to low regen and see what happens.
     
  11. randall_s

    randall_s Member

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    I've heard a faint "whine" recently at low speeds definitely on regen, but possibly off regen too. It sounds to me like gear noise/whine. I'll try to get a recording of the sound and post it. I have about 8,000 miles on the car with mixed driving.
     
  12. MikeC

    MikeC Active Member

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    I had a grinding sound around 30-40 mph when accelerating which was even louder when decelerating and regen kicked in. It was thought to be the "milling noise" and my drive unit was replaced, but it continued to occur. They eventually found out that the right front wheel had a broken bearing.
     

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