One problem related to noises during shifting has been reported for the 2011 Nissan Altima. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Nissan Altima based on all problems reported for the 2011 Altima.
When it is hot outside and the car has been driven for a long period of time the cvt transmission will make a whining noise. I noticed it when I was on the highway going about 70 mph. Because of this strange noise, I exited. When I was going 30 mph+ and accelerating the whining continued to happen. I am not sure what would cause this, but it sounds like a belt inside the transmission is slipping. It now stutters at times when going about 10 mph. When "shifting" down from 20 mph it will jerk.