​​​​​​Hello, Thank you so much in advance for your input....a few weeks ago, my car started to rattle when I would be idling. I thought it was my timing chain; however, upon removing the cover, I do not believe that is it. The two rockers removed were very loose; that is what we believe the sound was. My question is, how bad is the Camshaft scoring? Should I replace it now? My car is at 84k miles right now. I take such good care of it. I am planning to replace the timing chain in December as a preventative maintenance item (or before 100k miles).
Aside from that, How does my engine look? Any information and opinions are appreciated!! Thank you so much!
this was about 10k miles ago

 

I'm not an expert but you don't have any replies. Looks normal/nominal/norminal to me. If you were to try and measure those against a dimension, I bet you couldn't measure a difference versus new. Also, slightly worn cam lobes wouldn't cause a rattle. A loose rocker might.

 

Your roller-rockers are loose because the valve seats have dropped where the rocker arm is loose. Dropped valve seats are very common on N12, N14, N16, & N18 engines. I've seen this many times. Look carefully at the height of the valve spring on the opposite intake valve (same cylinder), and compare with the height of the valve stem where the rocker arm fell out. You'll probably see a noticeable height difference. See, when the valve seat drops the valve cannot return to it's normal position, this leaves a gap between the tip of the valve stem and the tip of the rocker arm. When there's a gap, the rocker falls out.

The only way to fix this is to remove the cylinder head and take it to the machine shop that has experience repairing N series engine cylinder head valve seats. Request all valve seats be replaced with the deeper seats. Factory seats are only .22 (intake) and .23 (exhaust) deep. The deeper seats are .035. Trust me, if you nickle and dime this, and only replace the seats that have fallen out, you'll be pulling the cylinder head off again in < 5k miles.

As far as the lines in the camshaft lobes; if you run your finger nail over it and you can feel it catching, it probably should be replaced.

I just posted a new thread related to valve seats; there are pictures that show the differences between the valve seats.

https://www.northamericanmotoring.co...lve-seats.html