Mercruiser 5.0 erratic clanking noise

[nuron]

I was idling my Mercruiser 5.0 305 last week in preparation of taking it out and suddenly heard an erratic clanking noise that I'm hoping you guys can help pinpoint. It goes on and off, and sometimes even becomes rapid (3rd video). In terms of maintenance, I've changed the oil + oil filter, fuel filter, thermostat, and coil wires throughout the span of a few weeks ago. The engine's probably idled for a total 40 mins while I've done all these tasks--can the constant idle cause this issue? I'm thinking the oil pressure is not getting to all the crevices and ports, and is starving a component of oil. Would putting the boat in the water and revving it for 30 secs - 1 min to 'clear out' the system be worthwhile to do?

Here are the three videos:

https://streamable.com/uel4h?fbclid=IwAR3xSn1CVMATBjdQZk4CFxu04ozF2t_lxq02NzPlvyF1xfj4JE4GPtbFX8A

https://streamable.com/9b4bs?fbclid=IwAR3xSn1CVMATBjdQZk4CFxu04ozF2t_lxq02NzPlvyF1xfj4JE4GPtbFX8A

https://streamable.com/xwngy?fbclid=IwAR0JUhWWScJYh5iUhrYPwVO7_EJG6IW6WH20hWkvVjukV8w4SjMzdUKQZUE

Thanks in advance.

 

[Bt Doctur]

I don`t see much oil squirting out of the rocker arms. whats the oil pressure read?

 

[alldodge]

Look around the flywheel area, think this is something loose and not inside the motor

 

[nuron]

I don`t see much oil squirting out of the rocker arms. whats the oil pressure read?

Boat gauge reads 40psi. I know a mechanical gauge is more accurate but the first two videos are only about 30 seconds of idling so that is why you might not see too much oil flow. The third video shows a bit more oil flow as we've given time for the engine to pump it through the system.

 

[nuron]

Look around the flywheel area, think this is something loose and not inside the motor

Since your reply, I have seen a lot of posts regarding flywheel noise similar to mine. Is there an easy way to check without pulling the engine? Or should an inspection mirror be used?

 

[alldodge]

If you can remove the dust cover on the bottom, there might be a chance