One problem related to engine rattling and whining sounds 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.
While driving to florida from DC for vacation, the engine started making a rattling noise. Since we were on a trip, I figured I would top off the engine oil just in case. The engine was bone dry. The noise seemed to go away after adding oil at first, but then the noise became louder, and the engine light came on. We took the car to the nearest dealer we could find. When they lifted the hood at the dealer, the oil had exploded and was everywhere. We were told there was catastrophic engine failure in my 2008 Sentra, but they could not determine the exact cause. Since I did not have my maintenance records with me (I was on vacation), they refused to even contact Nissan warranty without proof of all oil changes. They claimed the engine failed due to lack of oil changes. I could not afford a factory engine, so the purchase of a used 2008 Sentra engine voided my extended warranty. At the time of failure, the car had a little over 35k miles. Further research online indicates a possible oil consumption issue, which the dealership denies.