Minivan pumps are as noisy as a Dremel. Start the van and go sit in the
liftgate area or anywhere behind the vehicle. Something that is buzzing for
15 minutes after the vehicle is shut off aint right. When you turn the key
to on, before you start it, the fuel pump will run for a few seconds to
pressurize the system.
Ignition and fuel pump noise in the radio have never been a problem in my
vehicles, so someone else can tell you how to chase it out of those S body
vans.