Q: What may be causing oil to collect in the air cleaner housing on my car?
A: The most common suspect is the PCV valve. PCV stands for Positive Crankcase Ventilation. This little component is responsible for keeping crankcase pressure in check and recycling unburned fuel. An important component in the emissions system, the PCV valve reroutes any unburned fumes from the crankcase caused by blow-by to the intake manifold. Once in the intake, the fumes are eventually combined with the air/fuel mixture in the combustion chamber and then burned. This process minimizes hydrocarbons and other gases that are released into the atmosphere. The PCV valve is usually inserted in or near the valve cover.