Volkswagen: 2000 VW GOLF, input shaft, ray wright

Question
HI JOHN, MY SON HAS A '00 GOLF,I BELIEVE A 2.0.IT IS OVERHEATING.I HAVE REMOVED THE THERMOSTAT AND BYPASSED THE HEATER CORE.THE HEATER CORE ONLY BECUASE I CANNOT SEEM TO REMOVE THE AIR LOCK FROM THE HEATER CORE AND GET THE WATER TO TRAVEL THRU THE CORE OR BLEED THE SYSTEM IF YOU WOULD.THE WATER PUMP IS PUMPING THE WATER THRU THE SYSTEM AS I WATCH THE WATER FLOW.ALL BELTS ARE FINE AND I DID HAVE A MECHANIC LOOK AT IT AND HE TOLD ME THE SAME THING I'M TELLING YOU ABOUT EVERYTHING I CHECKED IS GOOD,SO,CAN YOU GIVE ME ANY OTHER IDEAS AS TO WHAT IS CAUSING MY PROBLEM AS I AM TOTALLY STUMPED AT THIS POINT IN TIME.ALSO THERE DOES NOT APPEAR TO BE ANY OIL IN THE WATER OR ANY WATER IN THE OIL AT THIS POINT EITHER.THANK YOU FOR YOUR TIME,RAY WRIGHT

Answer
it sounds alike the water pump, it is quit common. the water pump has a plastic impeller which expands as the cooling system heats up. this expansion causes the impeller to come loose from the input shaft. ( shaft spins but impeller does not ). Im sorry to say this is a poor design from volkswagon, i have personally done at least 2 dozen with the same faults.