Been a while since I was here last!
New issue i've been experiencing and having trouble diagnosing.
There's this "clatter" type noise I'm getting sometimes at idle and sometimes when shutting the engine off. Sort of like the sound a warped disc of metal would make scraping against a hard surface.

The issue started after replacing my starter after the starter got stuck and failed when a friend was borrowing my truck.
Starter works fine and seems to disengage (doesn't make that horrible noise a stuck starter makes) but now there is an intermittent clatter/rub noise.
I had a neighbor who is more mechanically inclined than me (aircraft mechanic) take a look, he inspected the flexplate for cracks and didn't find any, nor any damaged teeth.
The noise is more likely to happen when the car is parked facing downhill for some reason.

I'm still wondering if it is something with the flex plate or maybe something with the timing chain system.
I can't seem to find much info about the timing chain system and don't know if they run off of oil pressure or spring tension.

I also have an issue with oil pressure dropping at high RPMs but that may just be a bad sending unit. I have all new sensors just need to get them replaced when I have time to determine if there is an issue with the sensors or with the oil pump.

Any ideas? I keep trying to catch the noise on video but, of course, it refuses to happen when I need it to.