What Causes the Squeaking Noise When Braking and Releasing in BMW 3 Series?
3 Answers
BMW 3 Series squeaking noise when braking and releasing is generally caused by brake pad issues. Below are some explanations regarding the squeaking noise when braking and releasing in BMW 3 Series: Causes: For new cars, the brake discs and pads are brand new, so they need to be worn in. During this period, the brakes may produce abnormal noises, which can be categorized as vibration friction or sharp hissing sounds. These noises typically disappear after a few hundred kilometers. During sandstorms or in dusty conditions: Sand or dust particles may get between the discs and pads, causing a hissing noise when braking. Solutions: If the noise persists for a week or half a month and becomes increasingly louder, it indicates a fault with the brake pads. Otherwise, the cause may be something else, and the brake pads should not be mistakenly replaced. If a clunking noise occurs during sudden braking accompanied by vibration in the brake pedal, this situation can generally be ignored.
I've experienced abnormal noises when stopping and releasing the brakes on my BMW 3 Series, which is usually related to the brake pads. When new brake pads are first installed, their rough surfaces can easily produce sharp sounds when rubbing against the brake discs, but these noises typically disappear after driving about a hundred kilometers as the pads wear smooth. If the brake pads are severely worn, the metal layer directly scraping against the brake disc can also cause squeaking sounds. When you hear such noises during normal driving, you should check the pad thickness—generally, they should be replaced if they're below 3 mm. On rainy days or in humid environments, rust on the brake disc surface can worsen this issue, creating noise as the rust rubs against the disc when lightly braking. Foreign objects, such as small stones stuck between the brake pads, can also cause abnormal noises, often making more noticeable sounds when stopping and releasing the brakes. I recommend first checking the condition of the brake pads yourself, and if that doesn't help, take it to a professional shop for inspection. Don't delay, as it could affect braking performance and safety.
A friend who drives a BMW 3 Series told me that the annoying noise when braking to a stop and releasing is quite bothersome. Based on my own experience, I'll share some insights. The main reason is that the brake pads and discs haven't been properly broken in, such as with new cars or recently replaced brake components, where the metal surfaces aren't fully aligned, causing squeaking when braking. This usually improves after driving a few hundred kilometers. During long-term use, accumulated brake dust or loose caliper slots can make the noise more noticeable, especially during stop-and-go movements at low speeds in parking lots. In cold and humid weather, the disc surface tends to rust, and the sound occurs when rust particles are scraped off during braking. Don't underestimate this issue—it could indicate a problem with the brake system. Severe pad wear can affect braking distance, posing a safety risk. I recommend promptly visiting a 4S dealership for a comprehensive inspection. They can handle the cleaning, and regular maintenance should include attention to brake component cleanliness.
