Some possible causes:
* Low oil level: If the oil level in your engine is too low, the bearings will not get enough lubrication and can start to fail.
* Dirty oil: Oil that is dirty or old can also cause the bearings to fail.
* Worn oil pump: A worn oil pump will not be able to circulate oil properly, which can lead to bearing failure.
* Oil leaks: Oil leaks can also cause the oil level to get too low, which can then lead to bearing failure.
* Overheating: If your engine overheats, the oil can become too thin and not provide enough lubrication for the bearings.