A really loud noise inside the cabin that can't be heard from outside
 

Hi, does anyone know what is this noise? It happened 1 week ago and doesn't go away. It only appears when the car isn't moving, and it will be gone when I'm driving. This noise can't be heard from outside of the car, but man sometime it's really loud inside the cabin. It's 2012 G37 Sedan 7AT with 49k miles. Thank you guys.

Check blower fan.
Maybe leaves or mouse or stick got stuck in there?
Under glove box

I will. Thanks

Based on what he said "It only appears when the car isn't moving, and it will be gone when I'm driving." I don't see how a blower fan would cause this noise.

It's difficult to get a idea of where the sound is coming from in a video, Lee Nguyen can you identify where the sound seems to be coming from?

Is it towards the front of the car like engine bay? Behind the dashboard? Door panel?

It's difficult to make out what kind of noise it is in the video too. Does it sound like metal on metal vibrations?

Does it go away when you are in neutral or reverse?

Blown engine...

Oh okay.....

In the video, at the 0:04, you can hear it clearly. I think it sounds like the noise of 2 fans run into each others or maybe even the like the vibration noise. It's on the passenger side, but I can't tell if it's in the front or in the rear. It doesn't go away even when I put the car back into Neutral. It seems to go away for a little bit when the car is warm up, but it will come back after that shortly.

I wish I could offer advice but it's really difficult to diagnose a noise without actually being there to hear it for myself.

What puzzles me is the fact that you said it can't be heard outside the vehicle. Are you certain?

Have you tried putting the vehicle in park (it still makes the noise), getting out of the car and going over to the passenger side to kneel down to try and listen for it?

Does this noise occur only when the blower motor (a/c fan) is on? Or does it occur even with the a/c fan off? This way you can rule out the blower fan.

Impossible to keyboard diagnose lol
 

This is gonna need a.trained pro. If it cant be heard outside the car theres no way its not related to circ system or radio.nav system.

That noise can't be heard from outside the car, and it's still there even when I put the car into P. I guess I will have to bring it to a shop for them to see. I don't feel anything wrong with the car or losing power, but this noise just bothers me so much. Thanks for your help.

Try jiggling the washer fluid and some of the other parts in the engine bay held by those plastic rivets. Mines was the washer fluid funnel, rivet was broken and vibration was making all that sound.

So I did a lot of research as well as asking around the G groups, and I kind of have some possible problems:
1. Bad fuel damper
2. Damaged heat shield(s) (which I did hit one of my heat shield to the ground)
3. Bad cat
4. Broken metal part on the top of the muffler(s)
5. Well, something is broken in the engine bay.

id check blower fan under the glove compartment if youre saying sound only is heard in car

I did pulled it out to clean, but the noise doesn't go away. The noise seem to go away now when the car is completely warm up, but it will go back when the car doesn't move for a good amount of time ( I will say around 30 mins).

Id say it is a heat shield rattling the bottom of the car. Maybe you cant hear it on the outside because the cabin makes the noise louder than the force it really is