I have always had a clicking in my 235. I decided to look into it. I've checked my valve lash and I'm sure it's not that, there is a very loud clacking noise when the rockers are too loose. Different than the noise I'm talking about.

With the valve cover off, I narrowed it down to a specific lifter and rocker. When I push down in the rocker, I can actually feel the difference compared to the other rockers. The movement does not feel smooth like the others

I'm thinking its a sticky lifter but I'm not sure. Any ideas, thoughts or concerns?

I have added a video to provide sound.