TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here:

Noise when braking on autopilot

Discussion in 'Model S' started by ifonul, Jul 1, 2016.

  1. ifonul

    ifonul Member

    May 16, 2016
    I searched for a similar topic, but could not find anything similar.

    My S90D is a couple of weeks old now. I love everything about the car, but one thing nags me: when on AP, in stop and go traffic, the brakes engage - in a pretty abrupt way and quite late IMO - but what bothers me the most is a relatively loud 'thump' when the brakes engage. It sounds like a mechanical something (pump?) engaging (which would make some sense I guess), but it could also sound like a loose something (caliper holder?) in the braking mechanism.

    Now, the same *does not* happen when pressing the brake pedal, regardless of how hard of a stop. The sounds comes from the left/front (driver's) side. It also seems to be louder if there was an acceleration shortly after followed by a brake (to zero or close to 0mph).

    Anyone noticed anything similar to this? Not sure if I should be worried or just get used to it...
  2. kort677

    kort677 Active Member

    Sep 17, 2015
    #2 kort677, Jul 1, 2016
    Last edited: Jul 1, 2016
    I would advise to you get your car to a service center, what you are reporting is not normal and needs to be looked at.
  3. jdw

    jdw Member

    Jun 1, 2015
    Montreal, Canada
    Never hurts to have strange sounds looked at, however, I found that noise was coming from the brake pedal - Autopilot releases the brake abruptly and the pedal makes the thump sound as it returns the top end of its travel. It does sound & feel like it is happening on acceleration, as AP lets go of the brake and accelerates pretty much at the same time.

    You can verify that it is the pedal with your foot by not letting the pedal snap all the way back. The service centre (or you) can install a felt damper pad to mute the sound.
  4. DCGOO

    DCGOO Member

    Nov 24, 2015
    Indianapolis, IN
    What value of separation do you have set? (1 - 7). Perhaps something higher might work better

Share This Page