Sound from the 981

[equ]

The boxster started making a sound last week. It was about 50 or 100mi after I switched to the winter set, so I removed and reinstalled carefully. No change.

It's on the RHS only, I can't be sure if it is from the front or the rear. My first guess was a pebble between a rotor and the dust shield behind it which is super close. I looked, could not see it. I don't trust my lift, I took it to a tire shop and they looked, could not find a cause. They did not disassemble my calipers.

It's mostly at very low speeds and not always audible. It seems to come on when the car has been driven and it slows down. Nothing with engine, it goes with rotation, but not a wheel bearing. When I do hear it, it's worryingly crunchy, if it's not a stuck stone, I'm worried a bolt or a pin is backing out and scoring a rotor. But then it goes away at times, mostly when it's colder. I think it's the brakes as when I get on the brakes, the sound disappears. I also don't hear it at higher speeds, 40mph+.

I had work deadlines through Friday so had no time to call or go by shops. I guess I will try to troubleshoot it this coming week that I have off. It's also due for brake fluid at this point. I still have a lot of pad life visually at 30k miles. All parts are original to my knowledge at ten years old. Perhaps there is a stuck stone I cannot see? Or I lightly knocked something when I swapped wheels? Tire shop felt a lip on the rotors, thought the pad could make sounds.

[FC]

Generally, I'd go after it systematically, although perhaps you have already done that.

Is it better worse or varies when/if:

- Follows change in speed (does it follow engine or wheel speed)
- when turning (low speeds or high speeds)
- Warm or cold
- on the gas
- coasting
- on the brakes (light or hard)

But based on what you've reported, I'd pull the wheel and check out the pads, particularly the inside one. Did you check for and see anything of note on the inside of the disc?

[equ]

Originally Posted by FC

Generally, I'd go after it systematically, although perhaps you have already done that.

Is it better worse or varies when/if:

- Follows change in speed (does it follow engine or wheel speed)
- when turning (low speeds or high speeds)
- Warm or cold
- on the gas
- coasting
- on the brakes (light or hard)

But based on what you've reported, I'd pull the wheel and check out the pads, particularly the inside one. Did you check for and see anything of note on the inside of the disc?

I described most of this but maybe not systematically.
* wheel speed for sure when it happens, irrelevant to revs, gear or clutch
* low speed, when warm and only sometimes
* could happen when on gas or coasting
* getting on the brakes cancels the sound

I cannot really look at the dark side of the rotor or the inboard pads. I only have a hydraulic lift and no stands. While I'd like to solve it, it's not worth getting under the car. I've never pulled pads on a car, so I'm not about to do that on the 981. To the shop it will go... I think may be a pad is not really in place. The lips on the rotors (from wear) are about equal to my inexperienced fingers.

[FC]

What you describe sounds a lot like what happened in my Miata.

This is what the (inside pad) looked like. There was a rock or something scoring the pad and disk.

[equ]

Update: I had a few days off around New Year's. I described the noise and made an appointment at an indie to bring the car in. Lo and behold, noise disappeared. I circled and circled, on the way to the shop to get it to come back, no dice; the mechanic effect. Indie did not want to open stuff up for a noise that is now gone... Maybe it will come back in warmer temperatures. Maybe the offending gravel dropped or got ground down. Who knows?

[FC]

Glad it went away. Hopefully that’s what it was.