Rusty water leaking?

So today a friend started her rover 200 diesel and have noticed a huge leak she has told me she cant drive far in it ( i think shes trying to say its drive able) I have been told that there is a metal pipe running across / near the gearbox which has all rusty water on and then there is a black box near it. Im just wondering what the pipe is for? I have had a friend go and look at it due to being busy and he thinks the thermostat is on the right side of the engine near the gearbox and had cracked ??



I am thinking he and she is going on about the pipes going into the heating matrix?



Were is the thermostat on rover 200 2l diesel?

from the last news http://ift.tt/1w7qReI

via IFTTT