Engine and gas smell through air vents

When I'm driving my 2004 hyundai tiburon gt tuscani edition v6 2.7L 6 speed manual at low rpms it sounds like something is grinding in the engine, should I be concerned about this? Can someone help me diagnose the problem

Also When im at neutral and my foot is on the brakes and I have the cold air on, I can smell gasoline through the vent and it happends only at that time