Quick Question re: rattling noise from glove box area and smoke from exhaust

[Morgenster]

Blue smoke or white smoke?

[ber55ber55]

Blue smoke or white smoke?

Well its kinda hard to tell. I can only see it at night when there is a car behind me with its lights on. It looks black to me. The other thing is.....its not consistant. Sometime i have it, other times i dont. The times i dont have it, i also have more power. When i do have it, it almost feels like the tranny is slipping, but it not.Recently its only been at the high end of the rpms, right before i shift. It dooesnt smoke in idle, it doesnt smoke in normal driving, it doesnt smoke at low rpms. It only smokes when im really lettin it rip. I mean im not that worried about it yet, but I just want to make sure its not the head gasket.