When you stop the engine something is rattling away just as the engine dies and it sounds like a spanner or an allen key jiggling away somewhere.

I have had similar with a Bmw,I dropped an allen key and it went down behind the alternator.

My 1990 w124 300d om603 has had a couple of injector lines not secured in their clips properly and they make a lot of noise,placing your hands on them will see them go quiet.

Not familiar with the 5 cylinder engine and the throttle linkage setup but what is moving around mid rocker cover between injectors at start of video .