My '08 Fit makes an odd tick-tock/clicking and sometimes an accompanying chirp sound, usually under acceleration or load on the engine at higher speeds/revs. It's noticeable but not extremely loud; rhythmic and stops once I back off acceleration; and it doesn't seem to impact performance (yet). Recently it became more noticeable and I heard the tick-tock sound at idle at one point, though not the chirp. But haven't heard it at idle since. It's not tied directly to the spinning of the engine, rather it seems like a separate component. I wondered about a pump or fuel injectors or something. The chirp almost sounds like something squeaking as it rotates every second or so. It's tough to reproduce in city driving (where my mechanic is) so if anyone has any input on what this could be it would help me describe it to him.