Nissan Alternator makes noise
Some owners of 2002-05 Nissan Altimas and Sentras report an alternator noise or whistling coming from the alternator after the engine is shut down. This is considered a NORMAL condition and is caused by the rotor “slow-down” function that is built into the alternator. Before you lose a gasket over this problem, note that other vehicles equipped with alternator decoupler pulleys also experience some noise after engine shutdown. Do NOT replace the alternator if you hear this type of noise.
© 2012 Rick Muscoplat