Various strange sounds the R32 makes:

*      Loud whirring just after unlocking and opening the door is fuel pump.

*      Quiet high pitched whirring from rear passenger seat area while car is running, fuel pump.

*      Clicking/popping from passenger rear just after start-up is Evap system leak detection pump.

*      Random interval clicking sound from passenger front under the hood, is evap system purge valve.

*      Quiet whirring and gurgling sound from driver side of engine bay after car is shut off, is electric aux coolant pump.

*      Very high pitched whine that varies with engine rpms, usually when lifting off the throttle. Source unknown, but it's normal.