BMW Engine Crankcase Breather O-Ring - Genuine BMW 11155A33228

Product Information

BMW Crankcase diagram for X5, M440i, 530i, X6, 430i, & more

The engine crankcase vent valve, also referred to as the PCV (Positive Crankcase Ventilation) valve, is part of a vehicle’s emission control system. It helps manage the pressure inside the engine’s crankcase by allowing gases that build up in the crankcase to be vented back into the intake manifold. These gases are then burned in the combustion process, reducing harmful emissions. The PCV valve also prevents oil contamination and helps maintain proper engine performance by controlling the amount of blow-by gases (unburned fuel and air mixture) escaping from the combustion chamber.

• Rough Idle or Engine Misfire: A faulty or clogged PCV valve can cause the air-fuel mixture in the engine to become unbalanced, leading to rough idling or even engine misfires, especially when the car is idling.
• Oil Consumption: A faulty vent valve can cause pressure to build up inside the crankcase, which may push oil out through seals or gaskets, resulting in oil leaks. Excessive pressure can also force oil into the intake manifold, leading to increased oil consumption.
• Sludge Buildup: If the valve is stuck closed or blocked, the blow-by gases can’t escape the crankcase properly. This can cause condensation and oil to mix, forming sludge inside the engine. This sludge can block oil passages, leading to lubrication issues and engine damage over time.

About Genuine BMW

The original parts used by BMW to build your car are available as replacement parts under the “Genuine BMW” brand. When ordering a Genuine BMW part you are guaranteed to get the same part that you would pick up from your local dealerships part department. Genuine BMW parts have been built to BMW’s stringent standards and are the same quality of the original parts used to build your Ultimate Driving Machine.

You may not realize this, but the parts that make up your BMW are not necessarily manufactured by BMW. No cause for concern, as BMW designs the part, hires a manufacturer, and ensures its quality to you. In fact, many of these manufacturers have been making parts for BMW for decades. In our industry these manufacturers are called OEM (Original Equipment Manufacturers), and these are often brands you recognize, including Lemforder, ZF, Sachs, Bosch, Valeo, Zimmermann, Siemens VDO, Corteco, and more. Don’t be surprised to open that Genuine BMW parts box and find an OEM branded part inside, simply with the addition of a BMW logo.

Be sure to keep an eye out for OE tags on our product pages to quickly identify parts coming direct from OE manufacturers. That extra bit of insight could save you some serious money while shopping! Refer to our OE Academy for further information regarding the OE/OEM tags throughout the site.