I have a 1999 grand prix GTP, I hit the gas and the car drives but I am at 5 on the rpm gauge and it will slowly start to roll and continue to roll until i let off, I don't want to push it or over work the engine, but I also don't want to take it to a garage and get screwed either. So any help as to where to start or what to argue with the mechanic with later would be much appreciated. Thank you.