Why does the car always make a squeaking sound?
4 Answers
It may come from the suspension. The car's suspension includes links, springs, shock absorbers, and stabilizer bars. If any of these components is abnormal, such as loose bolts, it may produce abnormal noises due to shaking. Here is an introduction about why the car always makes a squeaking sound: 1. Abnormal airbag clock spring: If the sound comes from inside the car, it may be due to an abnormal airbag clock spring below the steering wheel or the universal joint inside the steering column. Wear or failure of these two components can cause abnormal sounds. 2. Problems with the braking system: If the abnormal sound increases when lightly pressing the brake, it can be confirmed that there is an issue with the braking system. For example, excessively thin brake pads, uneven wear between the brake disc and brake pads, or faults in the brake caliper, master cylinder, or wheel cylinder can all cause abnormal noises in the braking system, mainly manifesting as sharp and continuous sounds.
My car repair experience tells me that car squeaking noises usually have several common causes. The most common is excessively worn brake pads - when the metal backing plate of the brake pad rubs against the brake disc, it produces a sharp squeaking sound. Another frequent cause is aging engine belts, especially that continuous squeaking during cold starts, which could be caused by belt cracks or tensioner pulley failure. Additionally, aging and cracked rubber bushings in suspension ball joints can produce similar noises on bumpy roads. A loose power steering pump belt can also create such abnormal noises. Finally, don't overlook the easily ignored cause of loose underbody protection panels. When hearing abnormal noises, it's recommended to note under what conditions they occur - whether when braking or on bumpy roads - as this makes it easier to accurately identify the problem location.
Last week, my car had the same issue, so I did some research. That sharp squeaking noise most commonly comes from three places: First, the braking system—especially the metallic scraping sound when lightly pressing the brakes while parking—is usually the brake wear indicator signaling it's time to replace the pads. Second, the belt system—particularly when the noise gets louder with AC on or while turning—is often due to aging or slipping alternator or AC belts. Third, the suspension system—if the creaking is especially noticeable over speed bumps—it’s likely the lower control arm bushings cracking from wear. I think the easiest way to diagnose is having someone listen outside the car for the noise source while you perform different operations, which helps quickly pinpoint whether it’s coming from the chassis, engine bay, or brakes.
I've been running an auto repair shop for fifteen years and have dealt with countless cases of abnormal noises. A squeaking sound is most likely caused by belt or brake issues. For belts, check if the alternator belt and A/C compressor belt have cracks or hardening. For brakes, see if the brake pad thickness is below 3mm or if the wear indicator is damaged. The remaining 20% of cases could be due to: cracked suspension bushings causing direct metal friction; insufficient power steering pump fluid; or even aging exhaust hanger rubber causing resonance noise. If the noise is more noticeable when the engine is cold, it's mostly a belt issue. If the noise persists after the engine warms up, focus on inspecting the brake system.
