intermittent knock, Please help!

[monty509]

Thanks for the replies, It'll knock both hot and cold, that video was literally the first 30 seconds its ran since late November. It has a lot of hours on it but the motor is in good shape. As for the oil it's hard to tell, I get do get some blue smoke so I'm sure i does burn a little. Thought that was more likely to be because of fuel/air mixture. The knocking started last October, it knocks while at idle and under power. After I took the video yesterday it idled for about five minutes without knocking. I shut it off added oil, changed my clothes started it back up and the knock returned and hasn't gone away. I checked the spark plugs, they're snug. Perhaps the crush rings are bad? Again thank you.