My 2000 GMC Sonoma's fuel pump has been whining really loud for about six months now. I haven't noticed any change in the performance of the vehicle but I was wondering if this sound means that the pump is going bad. It makes the same noise the whole time that the truck is one. How much is it to get a new pump put on by a mechanic and how hard would it be for a person like me who has only done minor work to brakes and little things like that to get the job done. Thanks.