Why Do Engine Bearings Get Damaged?
1 Answers
Reasons for engine bearing damage: 1. Damage caused by prolonged idling. When the engine idles for too long, it operates below normal working temperature. Incomplete combustion of fuel injected into the combustion chamber causes some unburned fuel to flow down the cylinder walls into the crankcase, breaking down the oil film and reducing lubrication effectiveness. 2. Damage caused by shutting down the engine immediately after prolonged operation. After extended high-load operation, internal engine components reach peak temperatures, especially in the combustion chamber. When the engine is turned off, both the cooling and lubrication systems stop working, trapping heat and causing temperature spikes that break down oil films on lubricated surfaces. 3. Damage from immediately operating at high speeds and full load after startup. Engaging in high-speed operation and full-load work without proper warm-up causes problems because the engine hasn't reached optimal operating temperature. Contact surfaces and clearances aren't properly seated, and cold oil's poor flow characteristics prevent proper heat dissipation from moving parts. 4. Damage from incorrect adjustments or operation. Improper crankshaft end play (either excessive or insufficient) leads to thrust bearing failure. Excessive clearance causes impact damage, while insufficient clearance leads to overheating and abnormal wear, particularly damaging the seventh main bearing. 5. Installation errors causing bearing damage. Connecting rod deformation beyond specifications, uneven tightening of bearing cap bolts, accidental damage to bearing backs during installation, or incorrect bearing positioning can all lead to premature bearing failure.
