When fuel is burned in your engine, it produces waste gases that are mostly vented out through your exhaust system. But some of these gases push their way past the pistons and into the crankcase. There, these gases can mix with motor oil to produce oil sludge, which can damage vehicle engine parts through corrosion and by clogging engine passages.

The PCV valve is a one-way valve attached to the crankcase. Waste gases exit the crankcase through the valve but cannot enter.

This little car part needs to be replaced regularly or it can cause some serious problems in your vehicle engine.