Great info on this topic. I am a brand new Blackbird owner and noticed the "knock at idle" right away. Same conditions that you all have reported. I work as a marine engineer and have lots of mechanical backround. My guess was a possible connecting rod bearing. I was preparing to strip the engine down this winter and overhaul it(27000 miles). I am gratified to see how many miles you can put on these machines without rebuilding them. Especially such a high performance engine. I guess now I can just skip it or maybe just overhaul it for fun. The knocking noise is very annoying since it happens at stop lights. Makes people think your on a pos. BTW I love this freaking bird! It stood up on me today pulling away hard from a stop sign-Whoohoo!
