I have a knock in the top of the motor, almost like under the distributer, I changed the sparkplugs. I just bought the car for my son, also thought the timing might be off, changed the oil, and looked for metal, but all I found was blue specks maybe from a seal not sure, but the oil light keeps coming on when I start it, not sure if its the head gasket, lifters, or a rod, the knocking sound sounds like a beat to a rap song, if you have any ideas would be great thanks