Why is there abnormal noise in the crankshaft bearing?

[MacElias]

Crankshaft bearing noise may be caused by excessive wear between the crankshaft journal and the bearing, resulting in excessive radial clearance. Below are the relevant details: 1. Fault phenomenon: Crankshaft bearing noise refers to the knocking sound between the crankshaft bearing and the crankshaft journal. It is a heavy, dull metallic knocking sound that increases with engine speed and load, often accompanied by a drop in oil pressure and engine vibration. 2. Handling measures: If this fault occurs while driving, stop the vehicle immediately and tow it to the nearest repair shop or manufacturer for engine inspection and timely troubleshooting. Do not continue driving blindly, as this may lead to severe accidents such as bearing seizure or crankshaft breakage.

[Nascimento]

The crankshaft bearing is making abnormal noises, and I think it's mainly caused by bearing wear or lack of oil. If the engine has been used for a long time, the bearing surface may be worn due to friction, producing a ticking sound. Insufficient lubrication is the most common cause, such as low oil level or poor oil quality, which reduces lubrication effectiveness and makes the bearing prone to noise during operation. Improper installation could also be an issue—if the bearing clearance wasn't adjusted correctly during previous repairs, it could accelerate abnormal noise. Ignoring this problem is dangerous: the increasing noise can interfere with driving and may damage other components, raising repair costs. Prevention is key—regularly check the oil level and quality to ensure the lubrication system works properly. If issues arise, don’t delay; seek professional repair immediately. Otherwise, engine overhaul will not only be costly but also disrupt vehicle use. Avoid overloading the engine and prolonged high-speed operation during daily driving to extend bearing lifespan.

[LeLilah]

Last year, my car had a crankshaft bearing noise issue, which was particularly noticeable during idling or acceleration—a annoying rattling sound. The main causes are usually insufficient lubrication or excessive wear, often due to delayed oil changes or clogged oil passages, leading to dry friction in the bearings. I ignored it at first, but as the noise grew louder, I had to get it repaired. Unfortunately, the bearings were severely worn, requiring a full shaft replacement, which cost me unnecessary money. Additionally, high-mileage cars are prone to this problem, as bearing clearances increase over time, causing noise—like my old car, which started acting up after 100,000 kilometers. Regular oil maintenance is crucial for daily driving. Avoid prolonged high-RPM operation to prevent such issues, as repairs can be troublesome and compromise safety. Now, I inspect proactively and head straight to the shop at the first sign of noise to avoid minor issues escalating. Driving conditions matter too—minimize driving in dusty areas to prevent contaminants from entering the oil system and damaging bearings.

[BrookeLee]

Crankshaft bearing noise is common in older or poorly maintained vehicles, mostly caused by lubrication failure. Insufficient oil or unstable oil pressure increases bearing friction, resulting in knocking sounds. Oil shortage may be due to oil pump issues or clogged oil passages, while wear is the result of long-term use. The noise becomes noticeable during acceleration, and continuous neglect may lead to internal engine damage, crankshaft deformation affecting power output, or even complete failure, doubling repair costs. For daily vehicle use, it is recommended to regularly change high-quality oil to maintain lubrication and cleanliness, and address any issues early to avoid delays. Check oil levels as soon as noise appears to prevent potential hazards, ensuring peace of mind and effort-saving.