Front End Noise During Hard Deceleration on AP

[John J]

I have a MS Raven LR without FSD. At times when on AP (which I use infrequently), I hear a sort of rattling noise from the left front when the car automatically decelerates rapidly. I cannot duplicate the noise when not on AP and I cannot consistently force the car to make the noise even when on AP. I have a service appointment scheduled, but I fear the tech may not be able to reproduce the noise on a test drive and therefore will not fix the problem. I would appreciate hearing from anyone who experienced a similar noise, especially if you identified the source. Thank you.

 

[Impala1ss]

Keep us informed. I have the same problem but mine sounds like the caliper is loose - only when the AP hits the brakes though.

 

[John J]

After forcing the noise several times, my guess is there is a master cylinder actuator that is activated only on AP that is making the sound, which is a rumbling noise as if a piston is being forced into a dry cylinder. The sound sometimes also occurs when the car comes to a stop and the brake is released. I have an appointment with the SC next Tuesday, but am thinking of postponing to comply with social distancing suggesting.

 

[Russell]

Have you ruled out the brake pedal?
When AP applies the bakes, the pressure holding the pedal up is gone, causing the pedal drop and make noise.

 

[John J]

Thznk you for the suggestion. I did not observe the brake pedal. I will try, but the noise appears to come from the front.

 

[John J]

I brought the car to the SC today. I was correct that the brake actuator is the source of the noise. I was told the noise is normal, but they will check it out anyway. This is the usual response I get when I think something is wrong: "It's not like other cars, it's a Tesla."

 

[John J]

I brought the car to the SC today. I was correct that the brake actuator is the source of the noise. I was told the noise is normal, but they will check it out anyway. This is the usual response I get when I think something is wrong: "It's not like other cars, it's a Tesla."

I got the car back. Sure enough, my car is supposed to make an annoying noise under hard automatic braking. I enjoy driving my Tesla, but beyond that my experience has been a huge disappointment.

 

[joseacosta3245]

I got the car back. Sure enough, my car is supposed to make an annoying noise under hard automatic braking. I enjoy driving my Tesla, but beyond that my experience has been a huge disappointment.

I have a 2017 and it also makes the same sound in AP in stop and go traffic during hard stops.