Sounds like what happened to my motor, timing chain guide snapped, went down and f*cked up the oil pump. I was a dumbass and ran it with the fucked oil pump, didn't care to investigate what the tapping noise was, a v8 dude I knew said to adjust the rocker arms and I laughed and said my motor don't have rocker arms, then racing a riced out mirage and FAIL, spun the 4th rod bearing. I know, I suck at life, but I'm learning the hard way.