Jeep Grand Cherokee 2007 Automatic Gasoline mileage: 300 KM or more 4WD Peace be upon you. May God bless you. Whoever has knowledge and knows about the American car, please tell me. I had an overheating issue that damaged the engine heads. I rebuilt it and everything is fine, thank God. But every time I turn the key to start the car and it starts, white smoke comes out of the exhaust, and then it goes away. It only comes out when the car starts. I want to know the reason. Whoever knows, please inform me.