1999 Land Rover Discovery Q&A

1999 Land Rover Discovery Question: I have a 1999 discovery II that keeps running hot. New thermostat & cap

stays cool when idle but when I drive about 2 miles it runs hot and I hear some knocking and see smoke on the driver side of the engine. -
Answer 1
possibly bad head gasket -
Answer 2
how many miles poss rad blockage -