Is this the idle tensioner pulley telling me its worn.. this is on a 2litre.. n the engine is also very rattly when it starts.

Ticking speeds up with speed.. its not the cams/tappets, u can hear its from under the belt cover.

my escort with the 130ps zetec did something smilar, the clicking is the belt being really slack due to the tensioner and the belt hitting the plastic cover. i would recommend replacing the belt and pulleys asap as it sounds like it has worn a lot, may be worth checking water pump too whilst your there.

hope this helps