What Causes the Metal Friction Sound in the Engine?
2 Answers
The causes of metal friction sound in the engine: If there is a sound of metal parts rubbing against each other when the engine is running during a cold start, it is usually a sign of damage to the bearings of the generator, water pump, or power steering pump. General situation: It is normal for the engine to produce some noise due to vibration, but certain unusual sounds may indicate potential malfunctions. For example, a high-pitched belt squealing noise is usually caused by belt slippage; a sharp metal friction sound during engine operation is typically due to damaged bearings in the generator, water pump, or power steering pump. Engine air leakage: If the sound is caused by air leakage during engine operation, it could be the result of a blocked exhaust system or a leaking/broken vacuum hose. If there are abnormal noises coming from inside the engine, these are usually signs of major malfunctions, and the vehicle should be sent for inspection and repair as soon as possible.
That time I was driving on the highway when I suddenly heard a sharp metallic grinding noise from the engine, which really startled me. I immediately pulled over to check and found the oil level was critically low—probably due to an oil leak or severe oil burning. This kind of noise usually indicates insufficient lubrication, causing direct metal-to-metal contact, such as worn crankshaft bearings or piston rings. Ignoring it could quickly lead to engine failure, and replacing an entire engine would cost a fortune! I remember a friend’s car had a similar issue—the repair shop diagnosed it as bearing wear, costing thousands to fix. My advice: if this happens, stop the car immediately, check the dipstick. If the oil level is normal but the noise persists, don’t push it—head to a professional shop to pinpoint the issue with a stethoscope. Regular oil and filter changes are the best prevention.
