Mam A/T po ba? When you put it in D mode while brake is pressed nagkaka vibration po ba? Bumabagsak po ba bigla ang RPM? If yes, the servo needs to be cleaned.. normal po kase is when you put it in D, your RPM goes up a bit then goes back to normal, but if it drops instead of going up, servo is usually the culprit.. This is just based on the vehicles we have serviced, especially with VVT-i nga po, a friend of mine visited us complaining that when he puts it in D, it vibrates, you can see the plate number vibrating, when in Idle may konting vibration narin kagad then mawawala pag nag automatic ang aircon. We just cleaned the servo, usually takes an hour. After non nawala na po.
Also you might want to have your engine supports checked. konting crack lang po magkaka vibration narin lalo na sa idle palang nararamdaman nyo na.