Any unusual sound in the car should immediately alert the owner, as it is often an early and significant sign of a malfunction. Identifying these noises can help prevent expensive and serious damage.
Noise from the chassis and suspension
Suspension and chassis faults usually manifest themselves when driving over bumps or going over road irregularities:
Knock on bumps: This is one of the most common signs of problems. A knocking sound when going over potholes or "cops" usually indicates damage to the silent blocks, shock absorbers or ball joints. Such defects cause the car to "roll over" or have a greater inclination on small bumps.
Buzzing sound: Damage to wheel bearings causes a characteristic buzzing noise. The intensity and frequency of this sound change in direct proportion to the speed of travel.
Crunching when turning: Noises coming from the front wheels may indicate wear of the constant velocity joints (carriage). A crunching sound, especially at large steering angles, is a sure indicator that these key components need replacement.
Signals from the engine and transmission
Uncharacteristic sounds from the powertrain and transmission require urgent attention:
Engine rattling: Defective hydraulic lifters (valve compensators) often produce a characteristic rattling or "knocking" engine.
Whistling and knocking: Worn pulleys and timing chain or belt problems can produce whistling or knocking sounds. These noises are critical warning signs that require immediate diagnosis.
A dull knocking sound when the engine is cold: A dull knocking sound from the engine when it is cold can signal a more serious internal problem and requires immediate inspection.
Crunchy noise in manual transmissions: In manual transmissions, a crunching sound, especially when changing gears, is usually due to faulty synchronizers.
Brake and exhaust system
A squealing or grinding noise when braking: This is a classic sign of worn brake pads. Metallic noise is caused by contact between the wear indicator or the metal base of the pad itself and the brake disc.
Increased exhaust noise: Increased exhaust noise or the smell of exhaust gases in the cabin indicates a leak or a puncture in the exhaust system.
Manifold malfunctions: Problems in the exhaust manifold area can lead to more serious secondary damage such as valve wear.
Recommendation
Any unfamiliar or unusual sounds are a reason to immediately contact a professional service. Postponing diagnostics in the presence of such sounds can lead to cascading damage and serious financial consequences.