I bought a 2007 Toyota Matrix with 266k miles on it 3 months ago. I'm currently replacing my valve cover gasket because it leaked. While I've got the valve cover off, I'm checking on stuff. I've determined that my valve clearances are within tolerances, so now I'm looking at the timing chain. I've watched a number of videos about how the yellow timing marks are supposed to line up. Here is a video by Peter Finn:
It took me some rotations to get the EX dot on the left cam, to line up with the dot on the right cam, with the 2 yellow chain marks at the top and visible. I figure all these parts have some period of rotation and it took a couple of tries to get things lined up. With EX dot lined up, my yellow marks are 2 links right of where they should be. I can't figure out how to inline my images, so please see attached thumbnails.
I'm a bit lazy and have not removed a spark plug to tell if my #1 piston is top dead center. I'm still going up a bit of a learning curve. I believe I have already found something wrong. Did the chain jump at some point in its lifetime? What would be the consequences of that?
The only symptom of any kind of problem anywhere, is I've got mild vibration when the car is idling. It's slight, but it's consistently noticeable and there. I've read in the archives that this is a common problem for people with this car. I have not thoroughly evaluated my motor mounts to determine if there's anything wrong with them.
Per another thread, I had a funny noise coming from my accessory drive belt area. The drive belt was very old and replacing it made the noise go away. The drive belt tensioner is an OTICS and might be original from the factory. I know that tensioners can cause vibrations as they fail, but I haven't determined whether this one does. Again, lazy. I know that if I remove the belt, I could narrow it down further, but I kinda wanted to pat myself on the back about that job and call it done.
So I'm really asking, what are the likely consequences of a chain having jumped 2 links to the right? Need to do triage on the urgency, if any.