After replacing my Run and Start capacitors at the advise of this website, the problem continues. The compressor chatters loudly, then the fan comes on and the chatter stops. The unit is a RUUD Heat Pump 12 SEER about 6-8 years old. I have two the same age no problems on the other unit
Heating & Cooling - Ruud - Handle Air Conditioner
Answers & Comments
If I were there I would do a pressure check on the system.
Then a locked rotor amp draw on the compressor.
Then a amp draw on the fan motor.
I would compare these figures to the specs on the service plate and look for a variance.
I would also thoroughly visually inspect the contactor for loose connections and pits or burns on the points.
I would remove the wire terminal cover on the compressor and check the wires and terminals for burns ,loose, or corrosion.
I would also do a mfd check on the replacement capacitor to make sure it is correct as well as capacitor voltage rating at 370 or 440 volts.
If all checked out OK I would add a start assist capacitor to the S/R capacitor.
If all this fails your compressor may be developing bad valves.