What Causes Abnormal Noises in a Vehicle's Engine?
2 Answers
Abnormal engine noises can be caused by carbon buildup in the throttle body, a blocked exhaust system, faulty spark plugs, among other reasons. The specific analysis is as follows: Carbon Buildup in the Throttle Body: Poor fuel quality or leaking valve stem seals can lead to incomplete fuel combustion, causing oil suction due to a malfunctioning recirculation system. Blocked Exhaust System: Prolonged use of leaded, low-quality gasoline can poison the three-way catalytic converter and DPF (Diesel Particulate Filter), leading to blockages, which in turn clog the exhaust pipe. Faulty Spark Plugs: Deposits on the spark plugs, black deposits on the electrodes and inside the spark plug, indicate an overly rich air-fuel mixture in the cylinder, spark plug erosion, or cracked insulator tips.
Back when I drove my old car, the engine suddenly started making a clicking noise, which gave me quite a scare. Upon checking, I found it was either a loose belt or a worn tensioner pulley—this kind of sound resembles knocking. It could also be a failed connecting rod bearing, producing a rumbling noise, which is even more dangerous and requires immediate repair. When the oil level is low, the engine makes a whirring sound, accelerating wear; if the valve clearance is too large, it results in constant tapping. Cooling system issues, like a faulty water pump, can also cause unusual noises. The key is not to delay! Unusual noises are often early warnings, and ignoring them may lead to engine failure or unexpected stalling. I recommend first checking the oil and belt yourself and listening for the source of the noise. If it persists, head straight to a repair shop for a full diagnosis to ensure safe and worry-free driving.
