on the focus 1.8 and 2l you have one breather on the rocker cover going to air box and one breather going from crank case - oil seperator (on front of block behind exhaust, pcv pushes into this) - pcv - pipe - to inlet manifold.

my 2l focus rocker cover leaks and i've had several new gaskets on it but i discovered in its history the heaters werent working at some stage and it was found by a garage to be bacause the thermostat housing had cracked and leaked all the coolant out. the engine hadnt overheated and is in perfect working order but my guess is as the rocker cover is plastic its warped and distorted it so it wont seal properly. i'm after a new one but ford want £190