I took the car into the dealership (Power Nissan Torrance) for diagnosis of this noise at 2500rpm when accelerating, and they found nothing. I got the usual dealer runaround when trying to get it fixed.

The sound started a few months ago, and it is quite annoying since 2500rpm is cruising speed (65mph) on the highway in 4th gear. The noise is constant at that rpm range.

I am pretty sure it is not the belts or alternator bearings making the noise. It might be coming from the air intake, but have no ideas on how to fix it.

I searched the other threads but couldn't find anything similar, so any help would be appreciated.

 

Out of curiousity, do you have an aftermarket cold air intake? or JWT popcharger? That can cause a whistle around that rpm (it does on mine)

 

Yep, I do. It didn't make that noise before, though. Maybe cleaning it will help, which I am set to do tomorrow. If it clears up the noise, I'll post here and let you know.

 

There is alot of resonating through the y-pipe at this rpm..If yours is a little loose inside it can make a vibrating/humming type sound..

 

Well, I just cleaned and oiled my popcharger and the sound is still there. I'll have my suspension and exhaust system checked next. Thanks for your input.