While trying to change the oil, I removed the wrong plug. I removed what I now know is the timing chain tensioner plug. When I removed the bolt, a spring came out, and then a rod dropped down. The rod didn't come out of the engine block, but i was able to spin it and noticed that it had some slots cut into it. I pushed the rod back up into the block and replaced the spring and bolt. My question is, did I do any damage. Does the position of the rod matter due to the slots? Or if it all fit back together, is everything ok. Thanks for your comments.