183k miles, has a quick knocking noise from the front of the valve cover. It's definitely not a rod knock or anything like that, kind of sounds like maybe the timing chain or maybe chain tensioner or possibly VANOS noise. What are some of the common noises in this area? What does a noisy vanos unit sound like?

When I got it it wasn't this pronounced I don't think. Maybe it's my imagination as I become more tuned into the car though.

I'll be pulling the valve cover to strip and paint it, so I'd like to take care of this if needed at the same time while it's off.

As usual, all work will be completed by me.