My '05 S with 82K recently started making some strange sounds from the engine somewhere. It started this right after the big cold snap we had. She was in storage and I gently started her up with no revving of the motor until I knew it was warm. Running Royal Purple 5-30.
The sound is constant. Engine speed does not change the pitch, loudness or anything. I can turn the steering wheel a bit back and forth and I think I only hear the electric pump whir. But when I shut down, the sound winds down after the pistons have stopped. Hard to explain the sound. Sorta like air rushing as a deep hiss. Now my power steering resevoir has liquid showing on the tip of the stick. Not up to or in between the level marks.

Otherwise, she runs as good as ever with no other quirks. Temp is dead on too.

Thoughts anyone?