engine knock
 

Needing help identifying engine knock:
I have a GC 4.0 with 161k, last week I changed the timing chain and gears. After replacing the chain the motor developed an intermittent knock. I have changed the oil to look for any metal and found none, I went over the flex plate bolts and although I found one lose it still knocked after tightening it.

Oil preasure is 50 cold 40 hot.
runs and idles fine
knock comes and goes when warm

any suggestions would be greatly appreciated