Constant humming sound from rear. fuel pump?

[Icelander_28]

before yall yell at me, i used the search feature and got nothing on this one.


here's the details. i just bought my '91(my first explorer) on saturday from a dealer i know and trust. i didnt notice the hum then, probably cuz i was lost in happy land, but sunday morning it was there. "it" is a constant low volume hum that never changes. doesnt matter what gear im in, what speed im going, sitting still, 4 wheel or 2. just hummmmmmmm. it sounds sort of like an electrical transformer on a quiet country night.
my guess is that its the fuel pump because my fuel gauge is wrong. when i say wrong i mean that it only works when the key is turned counter clockwise to the acc position. it reads dead empty when in any other positon. im guessing someone replaced the fuel pump, tank or something else and wired it wrong. but thats just a guess.
other than this minor problem and the damage to the drivers door and drivers side passenger door, everything seems to be in perfect shape! it was cheap, has low miles and plenty of power. i love this truck!


thanks for any help or ideas!

 

[falls guy]

It's probably just the noise of your pump. Lay underneith on the drivers side, have someone turn the key to the run poisition, you should here it for about 4 seconds. Once you start the truck you will and should here it steady. Some pumps are louder than others. Doesn't mean nothing, mine's noisy too, it's been running for over a year like that with no problems. Turn up your tunes!!!! As far as your gas guage goes, your sending unit is probably gone. Although it could be a bad connection at the plug located on the frame rail near the tank, or a bad ground strap.

 

[prozachappy]

First...no such thing as a dealer your can trust Usually...humming is a good sign that the pump is on its way out. I say usually because some pumps will be louder than others, especially if it was replaced with a cheapo. So it could just be a hummer...lol but...like I said tale tale sign of a pump going bad. As far as the gauge not working, probably a bad float (which is also attached to the pump). 3 options: 1st, I'd take it back to your 'trusted dealer' and have them check the fuel pressure and diagnose the problem. 2nd, you can leave it alone, some pumps will go another 1 or 2 years after developing the humming. 3rd, if your as **** as I am...and can't stand the noise and possible pump failure, then order you a new pump...and make it your very first project on the X
Not a hard job, just drop the gas tank...remove old pump...replace with new ! A little more detailed but very simple and straight forward. If you don't have one already, go down to your local auto store and purchase an Explorer Bible...aka...Hanes or Chilton manual...this will give you all the info you'll need on the explorer and then some!