OM617 - How to test for worn cam lobe vs. wrist pin bushing or other lower issue

[ryanjmsn]

Hi,

Have a loud metal knock......definitely doesn't go away with cracking injector lines. Saw @Jarods video and discussion on his nailing/knocking ending up being worn cam lobes and followers: Some ideas on a OM617 Knocking/Tapping/Nailing?

Here's his video (almost positive I have the same noise): https://youtu.be/zzLLIDDYk4o

After spending quite a bit on other repairs lately, I was hoping to avoid another 500-1k repair like replacing the cam, etc, unless I"m positive that is what it is, rather than something lower on the engine like wrist pin, etc.

Does anyone have a suggestion how to confirm it would be cam related vs lower end related?