I was in the garage last night and heard any abnormal buzzing. I was able to identify the source as this black box under my wife's car. It is located in the undercarriage near the spare tire well. The car had been sutting untouched for hours. The buzzing stopped a short while after locking and unlocking the car.

 

Any ideas what the long black thing is or why it would be buzzing? The car is a 2014 Forester.

Edited December 1, 20178 yr by Daskuppler

Hard to tell but that looks like a charcoal canister,that would be part of the evap system.  I'm not familiar with the newer subarus and their evap systems so i'm guessing here ..but it could be the computer was purging vapors from the fuel tank ?? even though it was off for hours ?? 

the newer models do something like a tank/purge/evap pressure test or w'ever.

Edited December 1, 20178 yr by 1 Lucky Texan

Is this vapor purge something that would randomly happen? Or maybe be associated with a temperature change?

I'm not 100% sure about subarud evap programming.

 

But on other Japanese cars, they have the evap system test run after it has been sitting for 6+ hours to make sure there is no movement in the tank, and the gas has stabilized in temperature.

 

The buzzing is normal.

check your owner's manual, might be called fuel evaporation leakage check system, or similar

Thanks everyone for the input. Seems to be a unanimous conclusion of it's normal and nothing to worry about