hi simon,

did you get your focus sorted out ? as i have
exactly the same fault with a 1999 1.6 zetec
focus. there is no limp home or codes issues.
thermostat, water pump & radiator have all been
renewed. the engine getting really hot but radiator & rad hoses staying cold. must be air in
system or a circulation fault.

Please let me know if you had any success& what the cure was.

Thanks

colin