One problem related to engine oil leaking has been reported for the 2003 Saturn ION. The most recently reported issues are listed below.
Oil started leaking on Saturday, took to shop on Sunday, they thought cracked head gasket. Went to Saturn dealer on Monday, they could not id leak, directed me to bring back in a couple days. Today they identified cracked cylinder head. Car has only 67,000 miles and has never overheated to the best of my knowledge. Block is cast iron, cyl head is aluminum. Quoted cost to repair: $2600, not under warranty and not covered by dealer.