My transmission has been whining in my GS on acceleration through first gear for a while now. Lately (past 2-3 months), I hear a noise at idle that I cant really explain. Almost like a knocking consistent with RPM, but not really. It definitely is coming from the trans and not the engine. As soon as I put it into drive it goes away. Trans shift awesome and fluid is at correct level and good color (change it every 20K). Car has 108k on it now and I drive it about 400 miles a week now. Wanted to see if anyone has had an issue like this before and is it something I should worry about. Any input appreciated.