your answer depends on which type of transmission you have. if you have an automatic you could be looking at some serious money! It sounds to me like you had better take your car to the nearest treansmission shop and I do mean NOW!! it could be as simple as a cloged filter in the transmission or the transmission may be low of fluid. if you have a manual shift transmission then the clutch is about to go out on you. in any case you had better get it to a transmission shop quickly.
Mickey-G TN
July 2008