Tick vs knock
Doesn't match timing chain rattle which is worst when engine is cold. Valve train noise usually sounds more like ticking than knocking. Piston pin and piston knock is usually the worst when the engine is cold. The power steering pump, water pump and A/C compressor can sometimes produce a knock. Connecting rod bearing knock is louder when the engine is unloaded. Main bearing knock is louder when the engine is loaded. The air conditioner compressor is useful in loading the engine when listening for knocks. You can use a two or three feet long hose to listen with and try and isolate the source of the knock. You can remove the serpentine belt and run the engine for a minute or two to eliminate the alternator, water pump, power steering pump and A/C compressor as the source. Has the knock gotten any louder in the last 24,000 miles?