Popping from engine bay

Alright today as I was pulling into sound I heard some weird sound from under the car that I cant describe, and then the engine started making this popping sound non stop. I have no idea what happened but it seems to be coming from the top of the engine. The car was only at about 1500 rpm when it did it, so I am so lost right now. The car is a 2000 GT with the 4.6l and a 5spd

i have the same problem with my 1998 gt