I know its not my Ford....But!!

My Golf VR6 is using water. I cant see any leaks from anywhere and temp is fine whilst driving, even when doing high speeds. She is using no oil and there is no mayo in the filler cap or any rainbow colours in the expansion tank. I really don't know where it is going? I have some Radweld here that I think I may try but would rather find the cause as not overly keen on using this stuff on my engine and rather find the cause.

I did Google this and someone had put down that they had a similar trouble and it was leaking from the water pump, due to the high temp where the water pump is it evaporates.....But I thought I would check here before I replace the water pump.

Thanks in advance for any help