I have a 2007 Ford 500 with 46K miles. The car seems to be reving up when I am in reverse and in drive. it seems to rev up and then engage.
I assume that you have already checked the level and color of the transmission fluid and found both to be normal. If you haven’t done this, then I suggest that you do so and report back to us with your findings. If the level is low, then that suggests that you have a leak in one or more of the transmission seals.
But–Isn’t this car still under the factory Powertrain Warranty?
If it is, I suggest that you get the car to a Ford dealer a.s.a.p., as either a leak or any other transmission problem will be covered if you have maintained the transmission properly, as per the Ford maintenance schedule.
Regarding that maintenance schedule–does it call for a fluid and filter change at 30k miles? Even if it doesn’t specify this service at that interval, it is strongly recommended that you have the fluid and filter changed. Those who do not change their transmission fluid every 30k miles can expect to experience transmission failure anytime after ~90k miles.