Ok so I am at a loss at the moment.

While at an ATM with my window open I heard a ticking sound under the hood.

Opened the hood and heard the sound but it does not sound ominous.

However on occasion the Honda idles, how can I describe it as " rough ".

Light pressure on the accelerator and this roughness goes away.

Decided to open the oil filler cap on top of the motor and have a look.

First thing I noticed was AIR coming OUT of the filler cap opening with the engine running. This seems odd to me.

Second thing I noticed was a film build up on the underside of the filler cap. ( see pic below )

With a flashlight I peeked inside the filler cap hole with the motor running and it all looks clean as can be expected.

CAR INFO:
Year - 2013
Mileage - 40,300

Up to this point the vehicle has been dealer maintained as far as oil changes go.

ALSO - It has been extremely cold around here lately - not sure if this may have anything to do with it, like condensation of moisture or whatever.

 

Addition Info -

Car is operated in the " Economy Mode " 100% of the time.

Fuel economy seems to be as expected - except on short trips in town.