I have a 1995 civic with a 1.5liter 16 valve with 95k. It has a real loud knocking/rattling that comes and goes. Sounds like valve train. I pulled the rocker arm assembly apart and clean it because there was some sludge in there. But still no luck. I have adjusted the valves three times and tried three oil weights and its the same. It seems as the oil gets pretty dirty after 1k miles. Any ideas would help i just got the car a few months ago and did a head gasket. Let me know what you think thanks J

 

Check for bent valves and ignition timing.