1990’ 245DL

Ok, so I recently noticed a hum starting from the back of my car. It’s defiantly related to the fuel system i.e. In-tank pump or Main Pump. It’s loud enough to be heard while the car is running; however once I start moving at a decent pace it’s hard to hear, as the old brick drives and sounds like a tank. The sound is fairly new and I’m not sure if this is something that could cause a no-start problem in the near future, which would be very bad as it’s my primary and only transportation. Is this something that should be looked at, and if so is it an easy fix? I have enough car knowledge to get myself into problems. I can hear the noise from the back of the car especially when I remove the right side compartment cover and listen to the fuel filler pipe. The car drives fine and I haven’t noticed any effects yet.

Thanks so much,
Tom
Orlando, FL