how do you know when your oil pump is bad..i have a b18b.. and is the gasket reusable?

 

Could be different ways. The pump could not be building oil pressure cause the oil pump gear is bad, or if it is clogged somewhere. It sounds like you're having oil pressure issues. Another thing to look at is by dropping the oil pan and checking to see if the oil pickup is clogged or if there is debris. That can restrict flow. Hope this helps.