Tapping / Popping sound coming from underneath the car
I just purchased a 2013 Kia Optima 4 cylinder. After I shut the engine off
there is a light tapping / clicking sound that comes from underneath the car
(exhaust pipe maybe?). It sounds like someone is very lightly tapping metal
with a small wrench, and sometimes sounds like popcorn popping
(inconsistent, burst of pops then none, then two or three, etc.) The tapping
now occurs with the engine running. Any idea what this might be? I don't
think it's coming from the engine (valves, etc.) as I've heard that before and
it's not the same sound. Thanks, John