Mystery EJ253 Ticking

I’ve posted about this before along with a video of the sound but I’ll explain it here.

My ‘09 Impreza has a clicking/ticking noise coming from the engine.

From what I can recall, it has done this ever since I bought it with 94k (it has 135k now)

The ticking is most noticeable when driving up against something and I can hear it with the windows down. It happens when the engine is hot or cold and gets faster with RPMs.

It is also not a consistent tick, sometimes the tick is quieter for a revolution and louder for another, but it is there nearly every (second, not rod knock) rotation of the crank.

It is coming from the firewall driver’s side area. I’ve taken a stethescope to it and it is the loudest when placed on the top of the number 4 fuel injector. It can be heard when the stethescope is placed on the valve cover, but not loudly.

Oil is clean and the car runs very well.

I know these cars are typically loud and clicky but this one click is much louder and makes the car sound like a bicycle with a card in the spokes when driving around.

Has anyone dealt with this and actually fixed it?

My thinking is that if it was valve noise it would have gotten much worse by now. On the other hand, I’ve seen that fuel injectors can’t tick that loud even when they’re bad.

Everything else I can think of has been accounted for. New timing belt and tensioner, new manifold gaskets, etc.