There are several posts on this forum addressing knocking sound on the cool engine about 1 minute after start most pronounced during idle.
It sounds similar to the piston slap, however today I got a chance to use electronic mechanical stethoscope and was able to pinpoint the noise to the timing chain case (not drive belt idler!!).
So the noise most likely produced by chain vibration at certain rpms, not piston slap.

 

Awesome. With 167K miles I just carefully checked/adjusted valves, and afterwards when idling the engine to burp new coolant, after awesome startup sound, the ticking was so pronounced it almost alarmed me. I recalled that the Shop Manual states that the PCV valve should tick audibly. After this many high performance miles, I no longer care if the loud ticking is due to a dead skunk. When I am cruising about town and revving to 5K between shifts, the timing chain makes a really sweet whine. The car got 39 MPG recently on a 55-70 MPH run to Denali from Fairbanks with many tall hills. The most important skill that every Fit owner must master is DON'T BE ALARMED BY THE TICKING. It really doesn't matter. How the L15 Alpha runs when you beat the shit out of it is all that matters. The engine will never sound better than a Singer sewing machine. Honestly. Beats the hell out of logic...