What Causes Abnormal Engine Noises?
2 Answers
Here are the reasons for abnormal engine noises: 1. Engine oil: The noise heard when starting a cold engine is caused by ineffective oil circulation and lubrication. The sound will diminish once the oil circulates normally. 2. Exhaust pipe: If there is noise near the engine after the vehicle is turned off, this is normal. The sound is produced by thermal expansion and contraction of the exhaust pipe or heat shields. 3. Noise source: If the abnormal noise persists after starting the engine, it needs to be diagnosed based on the source. Worn components like the water pump belt tensioner or alternator can produce similar noises. If the noise originates from inside the engine, it is often caused by components such as valves or tappets. Other possible sources include fuel injector operation or high-pressure fuel pump operation.
As a seasoned driver with years of experience, I've encountered engine abnormal noise issues several times, mostly caused by internal wear. The most common is loose chains or belts, which produce a creaking sound. Over time, this can easily lead to slippage and damage the engine. Additionally, when the oil level is low, increased friction causes gears or bearings to wear out and make a clicking noise, requiring immediate oil top-up. Aging spark plugs or improper ignition can also cause crackling sounds, resembling popcorn. I recommend first checking the belts and oil level with a simple DIY inspection. If unresolved, promptly visit a professional repair shop to prevent minor issues from escalating into major faults that compromise driving safety. Remember, regular maintenance like changing oil and filters every 5,000 kilometers can minimize such troubles.
