what model is your mehran ?
is the fan automatic or direct.
Please check the following things:
a)if the fan is automatic check that it starts at the desired level of the heat needle in the car dash. usually water starts getting out of the bottle when the fan isn't working.
b)also go to some radiator wala and check whether the radiator cap is ok and isn't leaking pressure. also ask the guy to check if their is any rust in the radiator. because the orange colour of water may be due to rust or any coolant added.
c)go to some mechanic and ask him to check that whether ur car's head gaskit is blown due to heating or is still f9 .
i hope this helps.
and if its a new mehran get the problem solved immediately bcz once these mehrans give heating problems it becomes very difficult to bring them back to normal.
Good luck with the problem.