Severe oil leak causing the need to add up to one or more quarts of oil every couple of days. The oil leaks most when engine is off. The longer the car sets, the more the oil leaks, until it is all gone. Caused by extreme severe corrosion of oil pan. The corrosion is 'flaky' and pieces of the pan come off in layers. Oil seeps right thru the corrosion. The only solution is to have oil pan replaced, which is a major repair.