Engine is being replaced under warranty. At first I thought it was the High Pressure Fuel Pump as those are commonly loud on these vehicles, but after taking it into the dealer you can hear an audible difference of when the HPFP builds pressure but there's still a very loud noise coming from the top end of the engine. When the dealer took it apart, they removed the valve covers/intake and inspected the VCT Solenoids, which the screens were plugged with metal shaving debris. Because of this, Kia has decided to replace the engine under warranty.