So a while back I posted about a whirling/humming noise that I could hear coming from the back of the car(in the cargo area) at idle with everything off. I thought maybe it was the main fuel pump(aka the external pump) or the exhaust causing a vibration. It did not sound like any fuel pump noise I had ever heard before.

So today being board I decided to track down the noise. I let the car run while I had the tailgate up and held the exhaust pipe in the back. Nothing changed. I then climbed into the cargo area and found the source of the noise was coming from the area where the access port for the in tank pump is located.

I read everywhere that the external pump (main pump) is the one that makes noise when the in tank pump is dead. But I did not read anything about a noisy in tank pump. Are these in tank pumps noisy? or is this a sign of end of life? The noise is there whether the tank is full of gas or lower then half. It does not change in pitch or loudness. There is no driving issue(it drives like a tractor which is normal)

Any thoughts?

Thanks

 

Hi, all fuel pumps in the tanks can make noise: it could have a problem or it might be a fuel line touching a body panel which is acting as a sounding board to amplify the sound.
How old is the pump? If it is old, it could be nearing its end of life and have a noisy bearing. Does the sound come when the tank level is low? The fuel in a full tank often seems to reduce or dampen the sound. Also, sometimes the top of the tank itself becomes the sounding board. See if you can hold your hand or something against it and dampen the sound. I ran a Taurus we used at the office out of gas once, the pump was quite noisy with no fuel in the tank! no sound at all from the engine, though!
The pump of course runs at a constant speed, so the sound does not change, unlike a wheel bearing or rear axle bearing or a bad tire, which will change with speed.
I hope this helps you.