All engines allow some exhaust gases, unburned fuel and oil to “blow by” the pistons ... which is a source of varying air pressure, the PCV valve maintains the optimal level of vacuum in ...

Before the PCV valve was invented ... Additionally, engine oil would drip from the road-draft tube onto the roadway, causing a slick surface that could lead to accidents. The design that we ...

What is a PCV Valve? Save money on your next oil change by checking your air filter and PCV valve yourself and save unnecessary replacements.