The crankcase collects the combustion gases and to prevent it from escaping the crankcase is sealed. The Positive Crankcase Ventilation (PCV) valve is a one-way valve that ensures continual refreshment of the air inside an engine's crankcase. The PCV system acts as ventilation system so that the water vapor can be released so as not to form sludge. The water vapor and hydrocarbons are by-products of combustion that are collected in the crankcase which when left in the crankcase can cause corrosion. The PCV valve connects the crankcase to the intake manifold so that these unburned blowby gases can be burned again. Typical location of the PCV valve is the valve covers. The PCV valve is a spring-loaded valve with a specific orifice size designed to restrict the amount of air that's siphoned from the crankcase into the intake manifold. When the engine is not running, there is a low intake manifold vacuum that allows the valve to open and draw the crankcase gases and vapors to the intake manifold for burning. When the engine is at idle, the intake manifold vacuum is at maximum and pulls the valve plunger which partially blocks the opening, restricting the amount of crankcase gases and vapors drawn into the intake manifold. It is important to note that PCV valves are sized for specific engine applications. The wrong PCV valve for an application can cause flow that is too much or too little causing driving problems. It would be best to replace your valve because repair might cause clogging on the valves. When you want a replacement, be sure to take note of the size. Whatever the size, we have Eagle PCV Valve made from the finest quality with the superior materials available for you. You can place your order online or over the phone, you can also call our customer service for any assistance.