Mmarch97

So my 2005 Sierra with the 4.8 had the same issues. It got so bad that after driving just down the road I would lose oil pressure and the engine would be knocking like crazy. I did my research and decided it was probably the oil pump. After hours and hours of changing that out (this was a difficult job as stated before) I started it up and it was idling at 40 and was responsive and running good. Well the next day on my 30 minute drive home from work the oil pressure dropped down extremely low after I got off of the highway and the engine started knocking. It only does it after driving for about half an hour, at first start up and quick drives the pressure stays right above 40 and is running like a dream. If I would have known about these strainer screens I would have done that also but I'm not sure if that is the problem. Any and all input is welcomed!