i need to know if i need to replace my oil pump i was driving and the timing belt snapped because the exhaust cam seized up the front part were the oil seal sits was all melted. the car had had a over heating problem and set for a year before i started driving it i drove it a few times not to far just around the block after i fixed the water leak and it was fine. after that i drove it about fifty miles and thats when it locked up. is it because i didnt change the oil, the oil was low, or pump went out?