This guy has the exact same sound that mine has:
This morning it didn't make a noise.
But during lunch, and yesterday, it was as loud as this guy's (in the video).

Any ideas?

 

No it doesn't make the sound with the AC off.
SEEMS to be louder with the A/C turned all the way up.
Seems to be louder accelerating from a dead stop.

That video is the only way I can describe how it sounds (other than it sounds like an overheating Dodge Stratus engine).

 

Maybe a bearing is going bad or you need a new clutch? If you turn the AC off then the clutch shouldn't spin.

 

I found another thread on some forums. Someone requested that he (the guy in the video) make a video of it, and that video I linked was his reply
After reading through his thread, I learned that Infiniti/Nissan dealerships say this is "normal". No matter where you go, they won't do anything but let you waste money on it now.

People are saying they had compressors replaced and it didn't change it (which makes no sense). A lot of people, years ago, used their warranty to try and get this fixed.
No luck.

Others said they've driven their cars for years like this, and no issues. Guess my G35 will always sound like it has twin engines. Snapper lawn mower+VQ35 under dat hood

Honestly, I'm about done with it....

 

I've had my 06 for 10 years and never had any weird noises like that or on any cars I have owned prior. I find it extremely hard to believe it's "normal". I'd say either there is a restriction somewhere in the AC system or the clutch/compressor has issues.

I'd clean off the condensor (in front of the radiator).
Rent an AC manifold gauge and see what the pressure readings are.
Also, take a feeler gauge between the clutch and see the clearance.

I fixed my sister's AC problem on her Volvo with some zip ties and cut pieces of magnets from RockAuto, lol. Her clutch was out of spec due to the shims wearing down, so I did a ghetto fix that has worked for over a year.

 

I find it equally as hard to believe it's "normal" too.
Here's the primary thread I found:
https://g35driver.com/forums/g35-sed...g35-sedan.html

 

I'd take it to a shop that specializes in AC or do just searches about auto AC in general to help troubleshoot it. EricTheCarGuy has some awesome vids on his YouTube channel all things automotive.