Weird nose coming from back tire area

Whenever I drive for more than an hour, park my vehicle, and turn off the engine, I hear a weird nose from the back tire area. I don’t think it’s the tire, but cannot pinpoint the problematic area. The nose is wooooooooooooooooonnnnnnnnnnnggggggggg, and continues. I don’t know when the noise stops, but when the car is not “hot” the noise does not occur. I need help!

So the noise is there when the car is off and stopped? I suspect it is the fuel tank, probably venting, but I will have it on stands and listen from bellow and check for leaks etc.

galant may be onto something. Next time try removing the fuel cap.

Also tell us what make model year and auto or manual transmission you have.

I have 2000 Nissan Sentra, automatic transmission. I am going to try removing the fuel cap when I hear the noise. I’ll let you know if this helps. If removing the fuel cap solves the problem, what am I suppose to do? Do I need to fix the problem by replacing the fuel tank? Is it dangerous to continue to drive with such problem?