Volkswagen Repair: vw golf 1.9 tdi, vw golf 1, vw golf

Question
hi don,
i know this is not an air cooled system, but could not find how to ask question any other way.
1996 vw golf 1.9 tdi, loss of coolant.
i have to continually top up coolant.
there are no apparent leaks.
changed thermostat.
flushed out system.
there is a slight whining from the water pump area after approx. 30 mins/30 miles of motoring
oil is nt contaminated
any suggestions please, J.Atkins

Answer
John, thank you for your question.  The whining sound is probably an indicator that the water pump is going to fail sometime in the near future.  How long it will last in this shape is anyone's guess. It could fail tomorrow or next year even.  If you have more than 100,000 miles on the engine then more than likely the problem is the water pump.  They will last anywhere from 90,000 to 150,000, depending upon the climate that they are in.  
Hope that helps