Hard to say what the extra expense might be. My guess would be negligible. More like a point of perspective. Here you have a relatively new vehicle with an annoying noise, which admittedly it should not have. No one argues that the noise is normal. So, why can't it be remedied? Turning up the idle is not the fix, even if the original idle speed was below stock specs.
Resonance, harmonics, vibration, whatever. A rose by any other name... It doesn't make the noise when the engine is off, and does when it is idling. The engine is the source of the vibration, and some part of the vehicle is resonating to that vibration. Nissan can get as technical as it wants about the terms and descriptives, but the bottom line is that it is not supposed to do that, and they should make a good faith effort to remedy the problem. Unless, of course, they want to claim that whatever the noise is, it is not covered by warranty. Once they make that claim, contact an attorney.
The most likely culprit, assuming the noise is under the vehicle, is the exhaust, including something inside either the cat or the muffler. Second most likely are skid plates. Next most likely would be something that is touching the drive line that should not be. Isolating the sound should not be all that difficult if it makes the sound while parked at idle.
Resonance, harmonics, vibration, whatever. A rose by any other name... It doesn't make the noise when the engine is off, and does when it is idling. The engine is the source of the vibration, and some part of the vehicle is resonating to that vibration. Nissan can get as technical as it wants about the terms and descriptives, but the bottom line is that it is not supposed to do that, and they should make a good faith effort to remedy the problem. Unless, of course, they want to claim that whatever the noise is, it is not covered by warranty. Once they make that claim, contact an attorney.
The most likely culprit, assuming the noise is under the vehicle, is the exhaust, including something inside either the cat or the muffler. Second most likely are skid plates. Next most likely would be something that is touching the drive line that should not be. Isolating the sound should not be all that difficult if it makes the sound while parked at idle.
