Hey, I have a problem that is stumping me. When I shut my engine off I can hear a hum coming out of the rear of my expedition for 15-30 seconds. Fairly loud too. What could it be, fuel pump possible? The vehicle is running with no problems at all, but I have never encountered such a strange problem before. Any ideas, let me know.

Thanks.

Sorry, should have mentioned some specs
1999 Expedition XLT
4x4, 5.4L engine
anything else just ask.

 

Does it have rear air suspension? That will cause a little noise.

The fuel pump should only make noise when you turn the key on before starting.

 

nope, no air suspension