I am getting a disturbing new noise from the fuel pump during operation. Everything operates ok but I am hearing this noise at idle, kind of an intermittent 'burbling', like glug, glug, glug-glug, glug,etc. Should I buy a new fuel pump on spec or is there some other possibility. The car gets up and goes like always, starts fine, runs as well as ever. Just wondering if the pump is sending me a message. It has been in the car for about eight years and replaced the original which obviously lasted fifteen years.