Change the radiator.
However be very careful with this car. Freelanders with the K Series 1.8 engine are prone to head gasket failure - which may well be your problem. If that is the case you may find that you have a very expensive repair bill coming your way.
Either way that engine MUST NOT be allowed to overheat or it WILL blow it head.
I suggest that you get it to a Land Rover Specialist ASAP. It does not have to be a 'real' LR dealer a LR specialist independent will do but the garage round the corner will usually not have the expertise. But get it done NOW!
t, April 2008