I have a 2003 Sedan 5AT. A couple of times now when I have shifted the car into drive it has not engaged right away. For as long as I have had it (bought it high miles) the car has only been put in drive when it was sitting still or starting to roll forward. The most recent incident was the worst/slowest. When I put the car into drive and released the brake it started to coast forward (on a slight grade) I didnt do anything for a second then I gave light throttle. The revs flicked up to about 1.5k but no power was put to the ground. I quickly released the throttle and gave light throttle again, again the revs flicked up to about 1.5k then the tranny engaged, smooth and quiet like i would have expected as soon as i set it in drive. Any ideas on what this could be?