Struggles to accelerate quickly

[JordanMasse]

I have a 2010 Kizashi with 120K miles on it. One day I was driving on the highway and the car made a whining noise, like it was struggling to accelerate. About 20 minutes later acceleration stopped completely. I pulled off the highway and the car refused to move. I had shut the car off for a while and turned it back on and it started to slowly accelerate again. I was never able to make it go more than 40MPH. When I got off the highway, I was stopped at a light uphill. Once again, the car refused to move. I was stuck at the intersection and no matter how much I pressed down the gas pedal, it would not move. I sat in neutral for a while and revved the engine and after about 5 minutes the car was back to normal and accelerating perfectly fine. I have no idea what caused this. This was about 2 months ago. Recently I have noticed that the car does not accelerate as quickly as it used to, and after driving for 30 minutes or more, the whining noise returns but not nearly as bad. My gas pedal also feels harder to push down. Does anybody have any idea what this could be?

[KuroNekko]

You have an automatic transmission, I presume? These symptoms sound quite a lot like an overheated CVT (Continuously Variable Transmission) which is the type of automatic transmission the Kizashi has. The first thing I would do if I were you is get the transmission fluid flushed. If you've never had that done, it's certainly overdue. The interval for a CVT fluid change looks to be about 60,000 miles so you're way overdue if it's never been done. With new fluid, your transmission should perform better and keep from overheating as easily.