'99, 3.8l engine movement

ive got me a 99 with the 3800-II, when at a light or any time in idle, i feel some movement coming from the engine/tranny. its hard to explain but its the kind of movement you feel with a bad idle, but looking at the tach there is no problem. All the engine mounts are secure and are in perfect condition.

Is this something i should expect with this engine since the mounts are on the top and bottom? Im pretty sure its not my tranny because it drives smooth.