CUCV weird engine noise

Hello everyone, this is my first post

I hope you can help me with an issue I've been experiencing with engine in my M1009. Lately, I've noticed some strange like metal rattling noise that seem to be dependent on the engine RPM.
While driving it sounds more like vaccum leak (from drivers position), which has me quite concerned.

I decided to investigate further and used a stethoscope to pinpoint the source of the noise. It appears to be coming from the injector pump housing, as that was the loudest area when I listened closely. Also IP has a small leak from throttle shaft.

Has anyone else experienced similar issues with their engines? Could this be a sign of a problem with the injector pump, or is it something else (timing chain?) Is it safe to drive ?

Please check out video I made, linked below:

Any advice would be greatly appreciated.

Before you tear into the engine, I suggest you remove the belts to eliminate the accessories as a source of the noise, and carefully inspect the harmonic balancer for rubber degradation. Check the torque converter bolts for tightness and flex plate for cracks.

NDT said:

Before you tear into the engine, I suggest you remove the belts to eliminate the accessories as a source of the noise, and carefully inspect the harmonic balancer for rubber degradation. Check the torque converter bolts for tightness and flex plate for cracks.

Click to expand...

Harmonic balancer looks fresh, no signs of ruber deterioration.
Flex plate has no cracks and torque converter bolts are tight as well.
That noise comes from engine top