i did my first tire rotation on my 2011 civic(,front to back,)at 15,000 miles,,,i know, way overdue,and now i have a tire whine noise that starts at 35 mph,any ideas?

 

welcome to the forum. Honda cars do not alighn their vehicles from the factory. take your civic and have a 4 wheel alighnment done. rotate your tires each 5k miles. the whine may take a while before it ever goes away. also the next alignment tell them to swap the front left to the right rear, unless you have directional tires ( there is an arrow for the tires to rotate on some performance tires.) some rear axles on hondas have a minor off alignment within tolerance. You can check with the service manager if you have a warranty if the rear axle is out of alighnment. it takes minor shims but the labor is expensive if done without warranty.