I wouldn't call this a "little extra noise". I first knew something was up when some people crossed in front of me in a crosswalk and looked at the front of my rig with weird looks on their faces. I thought something must have been broken. I checked it out when I stopped and nothing was out of place.A day or so later I noticed a vibration while I was stopped at a light. I figured it was the cooling fan. When the fan comes on in my pickup, you can really hear it. I thought it must be the same deal in the QX4.
Then I got gas and checked my transmission fluid. I reached in to start the car, opened the hood and this fantastic buzzing sound started. I turned off the A/C and it stopped. I waited a few minutes and turned it back on and after about 15 seconds, it came back.
The clearest description of the sound is a buzzing sound. It is very loud and can be easily heard from 50ft away. My first thought was the fan shroud too, especially when I found a loose bolt. I have since tightened it down and verified clearances. It only makes noise when the A/C is running, but not always. It will always stop instantly when the ECON or OFF buttons are hit.
Oh yeah, it only seems to do it at idle.
