Low tone comes from back

[Wheel7]

Hi
1996 LX with 184,000 miles, does not have the automatic leveling. there is a low sound that comes from the back, almost like a cello note. It lasts for 1 second or less, and varies in intensity, may do it every 5 to 10 seconds but only does it sometimes. Doesn't matter what speed, once did it when I had it in park and idling, and I opened the trunk it was louder. Turning off the radio does not stop it. Car's performance is not affected by this noise. Has anyone ever had something like this?

[Blue)(Fusion]

Since it does it while idle and parked, it is not the rear end which is good news.

I'd venture to guess it's the fuel pump getting old. If it is the fuel pump, it can be replaced without dropping the fuel tank, although it may be easier if you drop the tank. Just make sure you replace with less than a 1/2 tank of gas.