Well after putting 16k on my truck I have a nice high pitch whine that increases with the RPMS. Was told by the dealership, that its the normal charactoristics of the motor and no matter what you do it'll never go away. Which I know is a bunch of bs. Contacted Nissan corp. still haven't heard anything back from them yet over this. I decided i'm just going to get a new truck, from a different manufacturer and do a valentary repo on this one.