Sometimes a blind squirrel finds an acorn.
I've owned a 2006 Vibe for about a month now. I've noticed that there is a "tick" in the engine, not unlike you would hear from a stuck lifter (if the Vibe had mechanical lifters). It bothered me, but I couldn't find anything, so I lived with it.
Today I changed the valve cover gasket. I did this because the coils were soaked in oil when I changed the plugs (great car buy eh).
When I took off the valve cover, I noticed a thin piece of sheet metal directly under the oil fill cap was bent in toward the cam shaft. It was not only bent, it had a scrape in it where the cam had been hitting. My guess is that someone shoved a funnel in the oil fill hole and bent the sheet metal so it came in contact with the cam. All I did was press the sheet metal with my thumb to bend it back and presto, no more ticking!
Bill