A significant part of these on-road emissions used to come from the crankcase — up to 30%, according to a 1962 study — but thanks to changes in engine design, that's no longer true.

The job of the Positive Crankcase Ventilation (PCV) system is to remove blow-by gases from the crankcase by vacuum and recirculate them via the intake manifold to be burned in the engine.

The positive crankcase ventilation valve releases exhaust gas and unburned fuel from the engine block into the intake manifold. All engines allow some exhaust gases, unburned fuel and oil to ...

“PCV” stands for “positive crankcase ventilation.” A PCV valve is an integral part of the positive crankcase ventilation system (PCV) system. It is also known as the crankcase ventilation system. The ...

Although some maintenance schedules include an interval for replacing the positive crankcase ventilation, or PCV, valve, others may not. In the latter case, a general recommendation is to replace ...

Crankcase ventilation is almost provided in all automotive engines. Its prime job is to prevent the dilution of lubricating oil present in crankcase which may lead to corrosion of crankcase metals ...

The engine used in this guide is a 4.9-liter inline-6 in a 1991 Ford F-150. This engine is also referred to as the Ford 300 . Finding and removing the PCV valve ...

Venting your V-8 engine is an important way to cure crankshaft pressure, and we take you step by step through the process.

BMW issued a recall for millions of its cars because of a safety risk and fire hazard due to an electrical short on its engines, particularly in its ventilation system that may result in ...

Air leaking into your car—not out of it—can be a problem. Popular Mechanics’s automotive experts outline the tools and techniques proven to smoke out even the toughest to find vacuum leaks.