What Causes Abnormal Noises After the Car is Powered On?

[LeDallas]

The causes of abnormal noises after the car is powered on include body noises and engine compartment noises. Body Noises: This issue is usually due to insufficient body rigidity, which causes the vehicle to deform during driving, resulting in friction or vibration between the doors and the frame, or loose welds leading to friction between metal sheets. Engine Compartment Noises: Some noise from engine vibration is normal, but certain unusual sounds may indicate potential faults. For example, a high-pitched belt squealing noise is typically caused by belt slippage; sharp metallic dry friction sounds during engine operation are usually due to damaged bearings in the generator, water pump, or power steering pump; if there is a hissing sound from the engine, it could be due to a blocked exhaust system, vacuum tube leakage, or breakage. If abnormal noises originate from inside the engine, these are generally serious faults, and it is advisable to send the car for professional inspection and repair as soon as possible.