I ride an '03 Ultra Classic. I recently, like less than a 1000 miles ago, had the cam shaft tensioners replaced by Harley. So a few days ago I noticed that when I started the bike up first thing the oil pressure wouldn't come up and I could here it knocking until I revved it up. But today I went to ride it and even at higer rpm's my oil pressure was low, under 20, and the oil idiot light would come on. So I'm wondering how do I determine if it is my oil pressure relief valve or my oil pump. When Harley replaced my cam shaft tensioners they said there was some metal in the oil pan, but none in the upper engine, so they just cleaned it up and I should be good to go.