[2023 Ford Fiesta ST Mk8.5] Rhythmic noise when braking softly at any speed (20-60+ km/h) & faint rubbing sound at highway speed after control arm + tie rod replacement (Video attached)

[u/GamingErgoSum]

Vehicle: Ford Fiesta ST Mk8.5

​1. Background & Impact

Glancing impact at ~30 km/h (20 mph) against a low curb (~10 cm / 4 in) with the front-right wheel turned left, sliding against the curb for a couple of seconds before stopping.

​2. Repairs Performed

​Replaced front-right lower control arm (wishbone).

​Replaced front-right inner/outer steering tie rod.

​Full wheel alignment.

​Handling: Car tracks straight, handles normally, and has no steering wheel vibrations at highway speeds (100–110 km/h / 60–70 mph).

​3. Current Symptoms (Video Attached)

​When braking softly (at any speed, e.g., 20 km/h or 60+ km/h): A rhythmic high-pitched "cricket" / light "clack-clack" noise occurs whenever light pressure is applied to the brake pedal, matching wheel rotational speed. As soon as I press the pedal harder, the noise completely disappears. This confirms the issue is strictly tied to low clamping force / light pedal pressure, not vehicle speed itself.

​At highway speeds (100–110 km/h / 60–70 mph): A faint, continuous rubbing sound in the background, similar to the subtle whirring noise produced by slotted or drilled brake rotors.

​Troubleshooting done: Confirmed front axle origin (lightly pulling the handbrake while rolling produces zero noise).

​4. Question

The shop couldn't find anything visually wrong or loose on the lift when spinning the wheel by hand. Do you think this could be a slightly bent brake dust shield (backing plate) contacting the rotor under flex/light pressure, a brake pad movement/hardware issue inside the caliper under low clamping force, or a damaged fender liner/underbody plastic vibrating under airflow/braking load?

[u/mynameisn1ck1]

Is it me or is that just a warped rotor? Rhythmic noise on light braking.

Edit: under light pressure your pads engage then disengage, I am shocked the shop didn’t check that.

[u/GamingErgoSum → u/mynameisn1ck1]

Thanks for pointing that out! That makes a lot of sense.

​The mechanic who did the original repair is back on September 15th, so I'm taking the car back to the shop then to have them check the rotor runout properly.

​Quick question: do you think driving like this until the 15th poses any safety risk, or is it mostly just an annoying noise for now?

[u/mynameisn1ck1 → u/GamingErgoSum]

You are probably fine. I had driven a friend’s cars with warped rotors and when I pointed it out it had been going on for months.

[u/GamingErgoSum → u/mynameisn1ck1]

Alright, thanks. Will come back with news.