Knocking from rear near fuel tank?!?

[marvlrose]

So I just got my 15000 mile service taken care of on my 2011 Rogue SV AWD and while sitting in the car after I got home I noticed a knocking coming from the rear. I got out looked around and took a closer listen and it sounds like its coming from the fuel tank. I stepped on the pedal to give it some more fuel and the knocking speed increased slightly until after about 2k rpms once released it comes back around the same rpm mark, slows down around idle and remains constant. I just wanted to see if anyone else had noticed this in their Rogue as well and if anyone has any input. Now before anyone make the statement, I would take it back to the dealer to get it looked at but the closest one is 2.5 hours away and I can only make the trip on the weekend due to work. Only if its serious will I be returning before my next scheduled maintenance.

Thank You,
Marvin

[casperfun]

Bad fuel pump, loose fuel pump, loose baffle or foreign matter in the tank.

[TaiLuu]

Fuel pump.
That will need replacing.
Don't pump gas a sketchy looking places.
Or have you ever ran out of gas?
Gas lubricates the fuel pump, so If you ever run out of gas it really messes up the fuel pump.

[marvlrose]

I had a feeling that it would prolly involve the fuel pump seeing as thats the only thing mechanical that functions in conjunction with the throttle. I haven't ever ran out of fuel but it has gotten low enough to turn on the fuel light like twice, three times at the most. Always fill up around half a tank and literally just filled it up before I got home at a reputable station in town. Good thing its covered under warranty... hopefully it holds out until I can get it back to the dealer. Thanks casperfun and TaiLuu for confirming my suspicion. I was really hoping it was just a normal noise from the lack of rear end insulation/sound deadening material in the rogue