A few weeks ago, I noticed that above 3000 rpm after driving for a while, my CVT is making a horrible whining noise. It is much more pronounced in manual shift mode I've noticed. Then, last week, I was driving and my CVT got stuck at around 1200 rpms cruising, and I pressed down the pedal but the rpms would not move. I jolted the pedal with my foot and the rpms jumped back up and things were normal again. This has happened 3 times now. I have a 2008 Altima with 102,000 miles on it's original CVT (as far as I know). Do I need to take it into Nissan? Is my CVT failing?