Zetecs run hot, its the nature of the beast.
there should be pressure on the cap, if there isn't, replace it
The two most common mods to help cool your engine down are;
1) Switch from stock 192 degree thermostat to a 180 degree thermostat
2) Add a bottle of Redline Water Wetter to the coolant


Frank McCoy aka Mod-deth aka Mid Life Crisis aka SVT Doood aka mcgainer is a SCAM ARTIST Pre98 Zetec - Some Mods