2009 Ford Crown Victoria - Knocks



I recently bought a 2009 Ford Crown Vic. After about a week, I decided to accelerate a bit quickly and immediately, the engine began knocking. It seems to be coming from the back of the engine bay, maybe somewhere in the middle. I’ve heard a variety of possible issues from a belt, cracked piston, and EVAP purge canister. The knock is inconsistent and seems to be the worst when I’m at a complete stop. What could it be?


Do you have a CEL on?