Where is the engine oil-gas separator located?
2 Answers
The oil-gas separator is generally installed at the crankcase breather port or exhaust pipe of the engine. Below is a detailed introduction to the oil-gas separator: 1. Function of the oil-gas separator: Maintains the good lubrication performance of the engine oil and extends its service life. When the oil-gas mixture enters the separator through the oil inlet line, it is sprayed onto the oil deflector cap (oil dispersion cap). The dispersed oil flows down along the pipe wall by gravity to the lower part of the separator and is discharged through the oil outlet pipe. Meanwhile, the gas, due to its low density, rises and changes its flow direction upward through the separation umbrella, adhering small oil droplets in the gas to the umbrella wall. The droplets gather and flow down along the wall, while the degassed gas enters the pipeline through the gas outlet pipe at the top of the separator for gas measurement. 2. Principle of the oil-gas separator: Separates the engine oil from the gas discharged by the crankcase, reducing the emission of oil from the crankcase breather port to the outside of the engine. Maintains good surface conditions of friction components, reducing wear and corrosion. Keeps the crankcase pressure basically equal to atmospheric pressure, minimizing oil leakage. Fully recycles mixed exhaust gases, reducing environmental pollution and improving engine economy.
I've worked as an assistant in an auto repair shop for over a decade and witnessed the varying positions of PCV (Positive Crankcase Ventilation) valves across different engines. Typically located at critical junctions of the crankcase ventilation system, it may attach to the valve cover or connect to the intake piping. In most vehicles, you can easily spot it under the hood near the intake manifold or firewall area – resembling a small filter canister or valve box. Don’t underestimate this component: its role is to separate oil vapor from air, preventing oil from entering the intake system and avoiding common issues like carbon buildup and excessive oil consumption. While placement varies, German cars often position it at the engine’s rear, while Japanese models tend to place it toward the front. For DIY inspections, regular cleaning every 20,000 km is advised, especially on high-mileage vehicles where clogging is frequent. Neglect may lead to abnormal exhaust emissions or trigger the engine warning light – proactive maintenance is crucial for safety.
