Where is the Crankshaft Forced Ventilation Valve Located in the Engine?
4 Answers
The crankshaft forced ventilation valve is located above the valve cover on the side of the engine. Here is some information about the engine: 1. Introduction: An engine (Engine) is a machine that can convert other forms of energy into mechanical energy. 2. History: The first external combustion engine was invented by R. Stirling in the UK (Scotland) in 1816, which was later improved by Watt into the steam engine. 3. Development: Engines can refer to both power generation devices and the entire machine including the power unit (e.g., gasoline engines, aircraft engines). Types include internal combustion engines (such as gasoline engines), external combustion engines (such as Stirling engines and steam engines), gas turbines (used in racing cars), electric motors, etc.
Last time I changed the oil, I specifically asked the master mechanic about this. The PCV (Positive Crankcase Ventilation) valve is tucked away near the engine valve cover. Pop the hood, and you'll see a protruding plastic tube on top of the engine—it looks like a little mushroom plugged into the valve cover breather port, usually connected to the intake manifold with a rubber hose. This thing actually works through engine vacuum pressure—it sucks out blow-by gases from the crankcase, filters the oil vapor through this small valve, then sends it back to the cylinders to be burned off. If it gets clogged, your oil cap might leak, and cold starts could get shaky. Some newer cars now integrate this valve with the oil separator as a single module hidden beneath the intake manifold.
A veteran engine mechanic with 10 years of experience tells you: The crankcase ventilation valve is usually located on the valve cover, look near the oil dipstick. In older vehicles, it's a standalone black plastic valve about the size of a fist - you can feel a spring-loaded flap inside that makes a clicking sound. Nowadays, German cars often integrate it into the valve cover itself, requiring removal of decorative covers for access. Last time I worked on an EA888 engine, its PCV valve was surprisingly hidden in the narrow gap between the intake manifold and firewall - took half an hour of disassembly just to reach it. Remember, this valve manages crankcase pressure balance. When clogged, oil will spray from the weakest point - like the valve cover gasket or turbo intake pipe.
Actually, the technical name for this valve is the PCV (Positive Crankcase Ventilation) valve. We test it daily during engine bench testing. It's typically installed at the highest point of the crankcase, and the raised section on the valve cover is specifically designed for it. The principle is extremely simple: when the engine inhales, manifold vacuum opens the valve, drawing crankcase gases into the combustion chamber; when you stomp on the accelerator, the valve instantly closes to prevent backfire. With today's stricter environmental regulations, some vehicles have a secondary ventilation valve installed on the turbo intake piping. Checking it yourself is easy: when the engine is warm, remove the vent hose and cover the valve port with your finger – if you feel strong suction, it's functioning normally.
