What is Bearing Burnout?
2 Answers
Bearing burnout refers to the damage of soft bearing pads caused by insufficient lubrication or excessive load, resulting in the crankshaft seizing or partially seizing. Symptoms of engine bearing burnout include: severe lack of lubrication oil during engine operation; degraded engine oil that fails to provide lubrication; low or no oil pressure while the engine is still running; presence of bearing alloy fragments in the engine oil within the crankshaft; abnormal noises during engine operation. Prolonged high-speed and high-load conditions can worsen bearing lubrication, leading to burnout. To diagnose engine bearing burnout: 1. Lack of or no engine oil: If the crankshaft suddenly seizes during engine operation, this directly indicates bearing burnout. 2. Abnormal noise: With engine oil present, prolonged operation may cause bearing wear, and the engine will produce a loud knocking sound that varies with engine speed, becoming louder with increased throttle.
In the automotive world, "bearing shell" (拉瓦) generally refers to the engine's bearing shells, which are thin copper pieces sandwiched between the crankshaft and connecting rods. I've disassembled many engines, and while these parts may seem insignificant, they are absolutely critical. Their surfaces are coated with a special alloy layer and rely on engine oil for lubrication to ensure smooth crankshaft rotation. If the oil is too dirty or the oil pressure is insufficient, the bearing shells and crankshaft will grind directly against each other, quickly wearing down or even melting. When this happens, the engine will produce a "clanking" metal knocking sound, and in severe cases, the crankshaft may be completely ruined. That's why every time I change the oil, I make sure the mechanic drains all the old oil thoroughly. After all, replacing bearing shells requires disassembling the entire engine—time-consuming and expensive.
