Oil filter screen

Hello,

This doesn't sound good at all. I am not sure what you mean by black rocks, but it sounds to me like pieces of metal or metal shavings from bearings. The only way to be sure of this though is to physically get into the engine and check the bearing for wear. Is your vehicle running rough or making any kind of noises, or have you noticed a loss of power at all?

Thanks,
Alex
2CarPros