If it's not a gasket = perhaps (it's a long shot) there's a casting flaw. At 94,000 miles Honda put a new engine in my G/F's Civic. Due to a casting flaw there was a tiny hole that leaked coolant. As soon as we found (which wasn't easy) the Honda rep. said, "put in a new engine @ no cost" = I know it's apples & oranges but a casting flaw can happen at anytime on anything.