Nissan 11810-86G00 Positive Crankcase Ventilation Control Valve Assembly

The crankcase emission control equipment consists of a positive crankcase ventilation valve (PCV), a closed or open oil filler cap and hoses which is meant to contain the gases that are formed in the combustion chamber during engine operation. These gases, if not removed from the crankcase, can get mixed with and contaminate engine oil leading to sludge formation are recirculated back into the engine combustion chamber where they burn up without escaping into the air polluting it. The process of recycling involves clean filtered air being drawn into the crankcase, picking up the combustion gases, and carrying them through the PCV valve and intake manifold to be used in the combustion chamber. This is a very important vacuum controlled valve in this system because it controls how much of these gases are returned to the combustion chamber. When blocked, there will be gas leaks through weak oil seals or gaskets in an engine, thus promoting sludge formation and causing oil leakage. This information along with troubleshooting instructions apply to any engine that has PCV system. To check for any leaks on hoses or connections, examine them for signs of vacuum leakages and replace or tighten as required. With all engines running at idle, disconnect the vent hose from PCV valve. If functioning correctly, there will be a hissing sound as well as strong suction from your mouth when you remove vent hose from PCV valve with your car at idle speed. In order to check for proper operation of this valve you should remove it and then blow through both ends . Air should pass freely through from crank case side but hardly move from intake manifold side . Should this occur , replace such a valve immediately . To remove PCV valve loosen clamp on hose and take off from manifold-crankcase hose as well as intake manifold . Just do installation like removal except disconnecting all hoses then use compressed air to clean them replacing any hose that cannot be blown out by air.

The PCV valve feeds crankcase blow-by gases into the intake manifold to be burned with the normal air/fuel mixture, and the valve, hose, and connections should be inspected every 30,000 miles or 24 months, ensuring all connections are tight and that the hoses are clear and not clogged, replacing any brittle or broken hoses. To check the valve's operation, remove the ventilation hose with the engine idling; if functioning properly, a hissing noise will be heard as air passes through, and a strong vacuum will be felt when placing a finger over the valve opening. On all Stanza models with CA20 and CA20S engines, a PCV filter is used, which can be replaced by removing the wing nut from the air cleaner lid, lifting out the filter mounted on the side of the air cleaner, typically about 4 inches long. To replace the valve located in the side or bottom of the intake manifold, squeeze the hose retaining clamp with pliers to remove the hose, unscrew the PCV valve with a wrench, disconnect the ventilation hose and clean as necessary, then install the new valve and replace the hoses and clamp. On the 240SX model, the PCV valve is located on the side or front of the intake collector assembly, while on the 200SX VG30E engine, it is found at the end of the ventilation hose coming from the rocker cover.