Thanks for the replies, so far. I would think even if it was the cam shaft, that is still a lot of vibration and would do some amount of damage internally over time, maybe I am wrong, it wouldn't be the first time (My wife would be quick to agree ha!). They definitely idle rougher then I though they would, while it isn't a huge problem, my mind just goes to things like is it the motor mounts ect ect ect? If this seems to be a common pulsing that others are feeling I guess I can write it off as a factory installed massager but I feel like I already paid the extra to GM for the happy ending