My home air conditioner that's inside the house, seems to be sputtering when coming on. What could this be?
If it sounds like liquid than I'd guess that the pump that circulates the coolant isn't being submerged properly when in its sleep state, and only once it gets a good vacuum and liquid pouring into its reservoir does it quiet down. I'd have someone check the fluid levels as you may need more of whatever coolant (Freon?) it uses.