Got a clicking noise coming from the engine on my 06 civic sedan lx too. Didn't have it during the first few months, but started to get louder and finally noticed it about a year later. I've searched online and got many possibilities on the cause, but most of them are just misguided on what the "clicking noise" is. Found a youtube video that may help:
YouTube - audi engine noise after lifter replacement
The clicking noise is around 14-15sec into the video. The vague background clicking is the noise that I have. It's vague in the video because of the low quality camera feed. Anyone know what the problem is? Or anyone experiencing the same with their 8th civic?
I'm gonna crack the engine cover up this weekend and see if the valves needs any adjustment. I'm hoping it's the valve because I don't know how to fix it if it's the cam chain tensioner, which is the cause of the clicking in that video.