I have an 04 g35 6 speed.

When I am decelerating coming to a red light or whatever and leave the car in gear letting engine slow me down I get a slight vibration as the engine goes past 2500rpm on its way down to stop when I press the clutch in.

I feel it a lot as I pull in neighborhood and slow down to take the turn to my street and I am in 2nd or 3rd gear. It is not a violent shake, but I can feel that there is smooth, then at 2500 rpm it vibrates some, then smoothes out again 200 rpm or more lower.

what could this be? or is this normal for this car?

Thanks

 

When was the last time you changed the tranny fluid? I don't recommend you to use the tranny to slow the car to a stop. You generate more wear and tear on the engine. Use the brake to stop the car.