Recently did a valve adjustment on my '91 RS Integra and about twenty miles it starts knocking a lil louder than usual ( always had a small rough knock during start but would get quieter ). I double checked the timing of the crank and cam, and even re-installed the timing belt to make sure. Checked valve lash - both intake and exhaust side were within spec. Pulled the head because I knew I had a bad HG and after pulling it off, this is what I found on the camshaft holder side on cylinders closest to timing belt:
The noise was coming from the head and as you can see in the pics, there are scoring marks from the rocker arms slamming against the head. What could cause this?
edit- I did mis-shift it once about 1-2k miles ago, but caught it pretty quick. it obviously went over redline
Whats going on really sounds like you might have a spun bearing. It knocks loudest at start and then as the car idles it gets quieter. (This has happened to me about 3 times already.) Best way to check this is take your oil pan off, (at this point check for metal shavings in the bottom in the oil pan. If there are any then this is a dead giveaway of a bearing(s) gone bad. ). Take off the oil pick-up tube and also the plate. Turn the crank with a 19mm ratchet at the crank pully till you have 2 push rods exposed and try wiggling the two FRONT to BACK (not side to side they all move side to side somewhat). then turn it again to expose the other 2 push rods and do the same thing. Any, and I mean ANY slight movement from front to back is a bad thing, and could possibly mean a major repair job.
