Is this a CVT quirk?

[Cristen]

Anyone else notice when idling at a stop light that the engine will be really nice and quiet and then all of a sudden it sounds much louder, and you can feel it in the steering wheel. Then anywhere between 5 and 30 seconds later, it will go all quiet again? This only happens to me when I'm stopped at stop lights. I've never had a car do that before. I've only noticed this in the last couple of months.

[philipa_240sx]

I don't think it's the CVT transmission...

If you have the HVAC controls set to defrost or defrost/heater, the A/C will start cycling on/off every minute or so (in cool weather). With the A/C is running, the engine is put under load causing the vibration. Next time try turning the fan OFF completely (it shuts off the A/C as well) to see if it does the same thing.

Why does the A/C run in defrost mode? It dehumidifies the air to improve the performance of the defroster.

Why has it recently started? There is an ambient temperature sensor that disables A/C operation in cold weather. With the warmer spring weather, the A/C is allowed to operate again.

While we are on the same topic...

If you select defrost mode, then switch to upper vents or lower vents (heater) the A/C light comes on to indicate A/C is still running. Reason: A/C operates in defrost mode and continues to operate even if you change to heater or upper vents to help dehumidify the air. You then have the option of turning it off by pressing the A/C button. In previous Nissan's (2000-2006?) the only way you could turn off the A/C was to shut the engine off! The Rogue is a huge improvement in this respect.

[Cristen]

So you are saying the AC runs no matter what? The AC indicator light is never on. I usually have the fan set to blow at my feet and windshield.

I guess I still have to get used to Nissans.

[Derango]

Only if you have it set to one of the defrost modes. Most cars these days do the same thing

[philipa_240sx]

Yes. This is common on all recent Nissans. It actually works well and defrosts the windows much faster than just heat alone.

[Cristen]

Cool! Glad I asked.