Lunge when starting

[Sugardaddy]

Hi I'm new on this Hummer site. As I was reading through some of the previous posts, I had noticed a post that mentioned that a member's truck lunged forward when starting. I am having the same problem as well. Was this answered? I don't want to repeat a post, but I couldn't find an answer. If not, allow me to describe my experience. I have had me 06 H2 for 4 weeks now, and the problem has occurred about 5-6 times. It seems to happen on intial startup in the morning. Just as the engine begins to fire and I let go of the ignition key, I hear a metal sounding bang and the truck lurches forward while in park. I called the dealer, but they said that they had never heard of such a problem. Any thought's? Thanks.