The positive crankcase ventilation valve (PCV) valve in the Ford Focus removes gas trapped between the piston and cylinder wall. Before the invention of the PCV valve, vehicles vented the gas, along with a small amount of vaporised oil onto the roadway. In the 1960s, the government passed legislation banning cars from dripping gas and oil onto the roadway, and the PCV valve was born. Because of this legislation, all late-model Ford Focus vehicles have a PVC valve. When the PCV valve on your Ford Focus becomes clogged, you must replace it.
Locate the PCV valve on the right side of the engine just below the right header. The valve presses into the oil pre-heater. Use the replacement valve for a visual aid.
Pull the breather hose off the Ford's PCV valve with your hand. Due to the fact the PCV system has very light air pressure circulating inside of it, clamps are not used to keep the breather hose and the PCV valve together.
Pull the PCV valve out of the oil pre-heater with your hand. Again, Ford did not install clamps to keep the PCV valve and the oil pre-heater connected.
Push the stem protruding from one side of the PCV valve into the oil pre-heater and then push the breather hose onto the stem on the other side of the PCV valve.
You can purchase PCV valves from most auto parts retailers.
Ford did not leave much room to reach the PCV valve behind the header. The area is very tight, and people with large hands may find it difficult to reach. However, the PCV valve is reachable without removing additional engine components.