Some causes of vehicle oil leaks are worn or improperly installed oil filters, broken oil pan seals and loose timing cover seals. A drain plug with worn threads can also cause oil leaks. Another common cause of oil leaks is a cracked, degraded or loose valve or oil pan gasket.
Loose bolts in the drain pan and can allow oil to slip out, causing leaks. A broken or missing oil filler cap can also lead to leaks. Physical damage to the bottom of the oil pan is another common culprit; rough roads, rocks, animals and branches can cause holes or cracks in the pan.