Mercury 4L5Z-6A666-AA Valve Assembly

You can Select Your Vehicle to check if 4L5Z-6A666-AA fits your vehicle.

Disconnect the PCV valve hose from the PCV valve, then rotate the PCV valve counter clockwise and remove the valve.

The main components of the PCV system are the PCV valve, a fresh-air filtered inlet, and the vacuum hoses connecting these two components with the engine and the EECS system.

The PCV system works by circulating fresh air from the air cleaner through the crankcase, where it mixes with blow-by gases and is then rerouted through a PCV valve to the intake manifold.

Reinstall the clean PCV system hose securely.

Carefully pry off the small round cap holding the PCV valve in place.

If no vacuum is felt, remove the valve and check for vacuum at the hose. If vacuum is present at the hose but not at the valve, replace the valve. If no vacuum is felt at the hose, check for a plugged or cracked hose between the PCV valve and the intake plenum. Check the rubber grommet in the valve cover for cracks and distortion. If it's damaged, replace it. If the valve is clogged, the hose might also be plugged. Remove the hose between the valve and the intake manifold and clean it with solvent. After cleaning the hose, inspect it for damage, wear, and deterioration. Make sure it fits snugly on the fittings. If necessary, install a new PCV valve.

The PCV system reduces hydrocarbon emissions by scavenging crankcase vapors. It circulates fresh air from the air cleaner through the crankcase, mixes it with blow-by gases, and reroutes it through a PCV valve to the intake manifold.

Inspect the fresh-air inlet hose and the PCV valve hose for cracks, leaks, and other damage. Check for obstructions inside the hoses and replace any clogged or malfunctioning components.

Installation is the reverse of removal.