My car leaks oil suddenly and stops leaking don't know if it is a valve pass

We need more info year module etc: There is a TSB SI B 11 08 09 Posible CAUSE and fix on these vehicles "BUT FIRST VARIFY LEAK" The POSIBLE cause is a very small leak at the main oil galley between the aluminum and the magnesium portion of the engine crankcase. PROCEDURE Do not attempt to reseal. Resealing may cause engine oil leakage to enter the cooling system resulting in contamination and further damage to the cooling system components. The engine crankcase will need to be replaced. This replacement requires a TeileClearing PuMA case Gene The Auto Shop

That is not normal.. You need to find the location of the leak and check the oil level right now. Get it in to make repairs ASAP. GL