2 weeks ago bought a 2017 Max Platinum and on the third day I started noticing a whistling noise coming from my air vent on the front right passenger side, keep in mind it does it whether the ac is on or off. It does get louder passing the 45-50 mph range. Idk what it is and it's really bothering me! I took it to the nissan dealer about on the 7 th day. I waited 2 hours till they told me to come back tomorrow so there best 20+ Plus years in the nissan buisness mechanic can take a look at it. So I did, the next day I waited 5 hours and they finally came out and told me first that you can adjust the up and downs to stop that noise and that it's completely normal for this car !!!???? But I did that even before I went to get it checked and nothing changed. I didn't argue and I left not one word out of me I was so angry ! but there gonna hear from me again ! I don't know anything about the car (speaking about the internal parts) but I'm pretty sure something (my theory) has to be loose inside the engine or not shut properly or something opened that's allowing air to flow once at high speed which then creates and air flow right into the right passenger vent having that whistle effect what should I do what should I tell nissan ??? This has to be fixed I owned brand new cars and none of them ever had such a problem or any problems at all really disappointed. This was my best purchase and car yet....

 

I am not an expert on these HVAC systems, but it may be that a baffle or other part may be somehow stuck in an immovable position inside the pipe to that duct. I would bet this will be a mechanical duct/baffle/etc problem rather than something to do with switches or computers or other electronics. Baffles are used to block, limit or allow air, depending on whether the system is in 'recirculating' or 'outside' air situation. None of those options should be causing noticeable noise, so I suspect a baffle is may be stuck in a 'between' situation.

Another remote possibility is that a dry leaf or some such item may somehow have gotten into the outside air intake, and the air rushing by it causes this noise. But I doubt that, because you seem to also get the noise with the air set in a 'recirculate' position, which should shut off anything coming from a stuck leaf.

The only way this could be electrical is if a wire is loose and is not reaching the device that opens or closes the baffle.

So your dealer says 'normal?' I suspect a few hundred posters here would beg to differ.

 

Have them pull the inside air filter out and then examine the airflow passages with a flexible shaft camera. It is not normal to have that noise.

 

Next time you speak to the dealer's most experienced Maxima mechanic ask him to take you out to listen to any other '16 or '17 Maxima on the lot. Bet your's is the only one with that whistling noise.

Question: If you totally close off that vent does the whistling go away? Does the noise change frequency in any way as you play with the vent louvers? There exists the possibility that the whistling is being caused at a point where the cabin air inlet meets the pressed-in vent louvers. Certain slight mismatches at this point can easily cause whistling. The vent louver is probably hand-pressed into place. Any way you can gently pry off the vent louver to see if it is, in fact, at the louver and not closer "upwind" to the blower motor?

 

I have same problem. My wife sits right in front of it on the passenger side she says she can't hear it.

 

Very good thought about the possible mismatching/improper connection of sections of the duct or connection of the duct with the vent louver assembly. That could definitely cause a whistling sound.

 

I have an SL and have the exact same issue on the right side. Mine starts whistling around 60 and gets louder as I go faster. It only happens when circulating air from the outside. I hit the button to circle inside the cabin and it stops. Very irritating.