Carrier compressor making noise

by Edward
(Atlanta, GA)

I have a <5 year old Carrier central ac system (not a heat pump). It is cooling fine, but when the outside compressor is running, it makes a loud noise I can best describe as sounding like a rattly old truck engine.

Every once it in a while, it will sound "normal", but not often. It almost sounds like something's out of balance like a washing machine spin cycle with too many towels.

I don't THINK it's the blower because the fan blades appear to be in balance and it's blowing hot air out as it should. I am concerned because it's not an old system. I would appreciate any feedback. Thank you...