Noisy Fuel pump?
 

Just acquired an 87 deville. It has a constant humming noise from the rear of the car. I assume it to be the electric fuel pump. Being a Cadillac I would think you shouldn't hear this noise inside the car, but it's quite loud. Does this mean the pump is due for failure soon?

Is there a possiblility of it being something else. I'm a novice with Cadddy's. I think this car has a self leveling suspension (seems' obvious by the light in the dash telling me the car is leveling). If that is run by a hydraulic pump , maybe that's the noise? Still I shouln't be hearing this running constant.

Kayladog