I wonder if I am having the same problem. When you say bang noise does it seem like the starter kicks back? I don't know how to explain what mine does other than "when it's it hot" and I go to start it, it almost feels like the starter is slipping or disengaging and trying to engage again if that makes any sense. I have an early morning doctors appointment in the morning and then I am going to run by the dealer to see if it will act up. I do have the extended warranty so I hope that helps with the cost.