What Is the Engine Oil Separator?
The engine oil separator is part of the crankcase ventilation system. During normal engine operation, combustion gases (blow-by) leak past the piston rings into the crankcase. These gases carry oil vapour and must be evacuated to prevent crankcase pressure build-up. The PCV (Positive Crankcase Ventilation) system routes these gases back into the intake manifold to be burned in the engine, reducing emissions. The oil separator removes liquid oil from the blow-by gases before they enter the intake, preventing oil from contaminating the intake valves and throttle body.
Oil Separator Replacement Cost in UAE
Oil separator replacement cost in UAE ranges from AED 150 to AED 500 for most Japanese vehicles. European vehicles, particularly BMW and Mercedes-Benz, have integrated valve cover and oil separator assemblies that are more expensive: the part alone can cost AED 500 to AED 1,500 on some models, with labour of AED 200 to AED 400. Volkswagen Group vehicles including Audi, Volkswagen, and Skoda also have combined PCV valve and oil separator systems that require full assembly replacement rather than individual component repair.
Consequences of Ignoring a Failed Oil Separator
Ignoring oil separator failure has cumulative negative effects on the engine. Oil vapour entering the intake system deposits carbon on intake valves, a particular problem for direct-injection petrol engines used in modern UAE vehicles (Toyota GR engines, Honda turbocharged engines, BMW turbocharged engines) where the fuel injectors do not spray fuel over the intake valves to wash them clean. Severe carbon deposits require expensive walnut blast intake cleaning to remove. Additionally, oil coating the throttle body causes a sticky throttle response and rough idle.