Any smoke coming from your car's exhaust is a cause for you to get your vehicle checked. White smoke generally reflect moisture in the exhaust system. This could be caused by a faulty or worn head gasket. Your engine cooling system carries the water and coolant to regulate the engine's temperature. It is also the only place water is supposed to be within your engine. When this moisture crosses into other areas of the car's systems, you need to be aware of the cause before it becomes a concern.