One problem related to transmission gear slipping has been reported for the 2008 Nissan Sentra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Nissan Sentra based on all problems reported for the 2008 Sentra.
On vacation left roanoke, va headed to gatlinburg, TN on the interstate just before getting off at the TN exit the transmission starts slipping, then stops working completely. Contacted the local TN Nissan dealership. Car was under warranty, all servicing documentation was provided supporting the transmission warranty. (you must have it serviced at some set number of miles or the warranty is void on the transmission. ) we were advised the transmission would have to be replaced with a brand new transmission. The Nissan dealership was unable to give us a rental, as they were already all out, for some event. We had to find our own way for vacation and getting home. (thankfully we had some friends that were traveling with us. 6 people in one car plus luggage!) went back got the car. Now this year we again leave for vacation and now we have an issue, cvt is going into limp mode is what I have heard it called. Car will not go over 55 mph. Contact the dealership when we returned. 3 weeks later a call and we are told they know about this issue in these models but they have no way to fix this issue even though its a new transmission, fluid changes help he says, and these cars don't like when there are 4 persons in the car. Really a brand new transmission and it has a problem they knew about but was still installed, as a warranty replacement. Broken transmission replaced with a known bad transmission?.