Whoever has newer Sentras, may want to check for this. Our 2005 has barely 10,000 miles. I noticed that the upper thin belt had not been installed on the pully correctly. The outer part was riding on the pully edge and the inner groove had no belt contact. The belt was tight. The outer portion of the belt was in shreds. Either the factory installation was incorrect, or the incorrect belt was used. When I brought the car in to have them change the belt under warranty, the service manager actually had the nerve to tell me that it is normal for the belt to ride back and forth in the pully from side to side and shred like that even at 10,000 miles. They tried to charge me for the belt replacement! I instisted that the service manager look at the car himself which he did. They reluctantly agreed to cover it under warranty as a one shot deal. I just couldn't believe that kind of treatment on a situation that was obviously a factory flaw. I also noted that the new belt did not overide the pully and filled all of the groves and appears to be seated properly. Just a heads up to check yours before you get stuck.