My accord is -09 2.2 I-DTEC exe tourer with auto transmission. I have noticed that when you park car or waiting on traffic lights, idle sounds good and very little vibration. When car stands on idle like 60seconds or something like that, idle drops like 100rpm (800->700rpm)lower and it makes vibrations to cabin. When you drive there is no vibrations or nothing. It happens only in idle. No difference AC on or off. So I wondering is this normal or not? It is very irritating. Some people say that is normal with automatic?? So if there is some kind of idle learning procedure, like to test it.