2016 Ford galaxy 2.0tdi Auto.(7 seater)seat/vw/c8

2016 Ford galaxy 2.0 tdi 300km Automatic and has been seiviced every 80k Timing belt has been replaced a few times Serviced every year Same owner past 7 year Was used as hackney,so was tested every year to keep it right @@ the car is loosing water,hense low price I don’t know what the problem is. Handy fix for a mechanic Would make good cheap family car Clean car