Does it go away when you press the clutch in? Having the same problem.Hi , I just got a 2013 civic si and while I am warming up the engine with the ac on the transmission makes a grinding/rattle sound, it goes away if I press on the clutch or drives for a few miles then everything sounds normal. Does anyone have this issue or this is normal for civic? I really don't want service department to open up everything on the brand new car as they usually do more damage then fixing the problem. Below is a link of the sound. Thanks for the help in advance.