The Zetec 2.0 litre dual overhead cam (DOHC) four-cylinder engine was manufactured by the Ford Motor Company and used in the Ford Focus from 2000 through 2004. This engine had an output of 130 horsepower and 135 pound-feet of torque, enough to give the Focus plenty of zip while still returning good fuel economy. The valve cover is mounted on the cylinder head on top of the engine with a rubber gasket. Over time, the gasket may become hard and brittle and allow motor oil to seep past the valve cover. The valve cover must be removed before the gasket can be replaced.
Allow the engine to cool for a few hours if the car has been driven recently. Open the bonnet and locate the spark plug wires on top of the valve cover. Label the wires with a piece of masking tape as to which spark plug each is connected to. Grasp one of the wires by the base and pull it straight up from the top of the engine. Repeat for the other three wires.
Push the throttle cable and the cruise control cable to the side so that the valve cover can be lifted up without hindrance from the cables. Locate the black air intake tube at the rear of the valve cover. Grasp the tube by the base and pull it straight up from the valve cover. Push the tube slightly to the rear of the valve cover.
Remove the ten 8mm valve cover retaining bolts with a socket and ratchet. Carefully pull the valve cover straight up and remove it from the engine. Clean the mating surface on the engine with a clean rag, being careful not to let any debris fall into the cylinder head. Pull the old gasket from the underside of the valve cover and discard it. Make sure to remove all the pieces of gasket from the mounting groove on the underside of the valve cover.
Press a new valve cover gasket into the groove on the underside of the valve cover until it is fully seated all the way around. Lubricate the gasket with a light coating of clean motor oil applied with a finger.
Replace the valve cover on the cylinder head, making sure all of the mounting holes line up. Replace all of the retaining bolts finger-tight first, then tighten them in a crisscross pattern with a torque wrench initially to 1.5 foot-pounds, then to to 5 foot-pounds. Do not over-tighten the bolts or the plastic valve cover could warp or break.
Push the Intake pipe over the opening at the rear of the valve cover until it is fully seated. Reposition the throttle and cruise control cables back in their original places. Push each spark plug wire back onto its corresponding spark plug until it snaps into place. Remove the masking tape labels from the wires and close the bonnet.