So our good car, our used Nissan Sentra that we bought in 2023 (and are still paying for) has developed a major transmission problem. We have been working to DIY the problem with out mechanically inclined friend, Steve. We have replaced a motor mount and finally zeroed in on the transmission being the source of the noise/problem.

It will need to go to a shop for proper diagnosis and estimate. Our best guesstimate as laypersons is the CVT flexplate. Repairs for this generally run between $1000 and $2000. The parts aren't terribly expensive but the labor is intensive.