I have a 2001 Chevy Cavalier 2200 SFI, my car had been overheating but couldnt find the problem. Then i found a crack on the valve cover so i took it off and notice almost no oil on the head. i turned the car on without the valve cover, nothing no squirt or nothing. So i took the oil pan off and the oil pump, then i found a hole and can see the cam. I dont know if thats normal.What could of caused the hole? any help, thanks

post a picture of said hole?