After many phone calls and visits to dealership nothing was done. I went on test drive with mechanic they definitely heard and acknowledge the constant buzzing and groaning. However, when I picked up the car they claimed they could not reproduce the sounds. Noises begins when motor is warmed up (40 Minutes); they obviously did not take the time to warm it up even though I specifically told them to do so. I reported this problem to the Toyota Customer Experience Div.; it took them several months before they came up with a solution. They were contacted the dealership's service dept. and parts were ordered. This problem was finally solved however, another noise problem started several weeks ago (loud thumping). This new problem has not been solved yet.