What Causes Abnormal Noises in Cars?

[CadenRose]

Abnormal noises in cars can be attributed to the following reasons: Body Noises: Body noises are the most common and are usually caused by insufficient body stiffness. Long-term aggressive driving or frequent travel on bumpy roads can lead to slight deformation of the car's steel frame. The most direct impact is abnormal collisions or friction between the doors and the car body. Additionally, abnormal friction at welding or screw points can also cause noises. Some cars may have louder wind noise, which is partly related to the car's design. Interior Noises: Interior noises are very common and can originate from multiple areas, such as loosely installed trim panels, a loose glove compartment, or impacts from seatbelt buckles. Brake Noises: If a "squeaking" sound occurs when braking, it is often due to excessive wear of the brake pads, creating unwanted gaps. Improper material use or deformation of the brake discs, as well as unqualified hardness, porosity, friction characteristics, or compression characteristics of the brake pads, can also cause noises. Generally, the lifespan of front brake friction pads is 30,000 kilometers, while rear brake friction pads last up to 120,000 kilometers. Suspension Noises: The suspension system operates continuously while driving, and the rubber bushings between the shock absorbers and various links will inevitably wear out. When these bushings age or fall off, abnormal metal collision sounds may occur. If the shock absorber is damaged, a "thumping" or "clicking" sound may be heard on bumpy roads. Tire Noises: Tire noises are usually tire-related and vary in intensity depending on driving speed, tire type, tire pressure, and road conditions. A low "thudding" sound often indicates tire tread deformation, bulging, severe wear, or insufficient pressure. A "tapping" sound may suggest small stones or nails stuck in the tread. If a metal collision or friction sound comes from the wheels while driving, it could be due to damaged shock absorbers or bearings. These issues should be addressed promptly, as even a simple nail puncture can be dangerous. Steering Wheel Noises: Noises may occur when turning the steering wheel. If the noise appears when the wheel is halfway turned, it is likely due to the steering gear. If the noise occurs when the wheel is fully turned, the source may be harder to pinpoint. A common diagnosis at a 4S shop is friction from the steering tie rod ball joint rubber sleeve. Other causes include leaking steering gear dust covers, loose or aged power steering belts. Engine Compartment Noises: Engine compartment noises are more complex and require thorough inspection. A sharp "screeching" or belt whining noise is usually caused by belt slippage. A hissing sound may indicate blockages or breaks in the exhaust system or vacuum tubes. If metal friction noises occur while the engine is running, it could be due to damaged components like the alternator or water pump. Transmission Noises: If a "rustling" sound is heard from the transmission while driving, or a whistling sound during gear shifts, it may be due to worn transmission bearings or gears, or bearing spots. Noises during acceleration or gear shifts may indicate the presence of metal particles in the transmission fluid, suggesting excessive wear of components like transmission bands or clutches.