Are you in search of a good workshop to repair engine problems in your Bimmer? You’re on the right track! Your BMW is made up of many small and complex components that make the automobile function properly, and one of them is the crankcase valve. A crankcase ventilation valve, also referred to as the positive crankcase ventilation (PCV), is a component of your BMW’s engine that manages the gases that accumulate in the crankcase, preventing pressure build up and allowing unburned fuel vapour to be recycled back into the intake. Through this process, the engine’s efficiency is increased and emissions are decreased.
When the PCV valve starts to fail, the symptoms become apparent and you may begin to experience different performance issues. Let’s see how BMW owners can tell when this valve fails, how to fix it, and where to go for the smoothest repairs.
Signs of a Failing Crankcase Ventilation Valve
- Excessive Oil Consumption: If your BMW is using oil at a higher rate than usual, then there is a possibility that the crankcase ventilation valve is damaged. Failure of the valve results in the drawing of oil into the intake system, which increases oxygen consumption.
- Rough Idling and Poor Engine Performance: If the PCV valve is not functioning correctly, it will result in an improper air to fuel ratio, and this will lead to situations such as rough idling, misfires, and poor acceleration. It is also common to hear your engine revving or lagging behind when the car is stationary at a traffic light.
- Oil Leaks and Sludge Buildup: When the PCV valve fails, it leads to the pressure build up in the crankcase and as a result oil is forced past gaskets and seals. This may cause leakage around the valve cover, intake manifold, and turbocharger. It can also lead to the formation of sludge inside the engine, blocking lines and definitely affecting the performance of your vehicle.
- Blue Smoke From the Exhaust: Another sign that may indicate that your car has a bad crankcase ventilation valve is blue smoke emission from the exhaust. This occurs when some of the oil is sucked into the combustion chamber along with the fuel and gets burnt. If you notice blue smoke, it means there is an issue that requires immediate attention.
How to Repair Crankcase Ventilation Valve That Is Not Working Properly
- Check the PCV Valve: If you think that the PCV valve is to blame for the problems in your BMW, then you should start by checking the PCV valve for any signs of wear or blockage. A damaged valve should be replaced with a genuine OEM replacement to ensure optimal airflow.
- Look For Signs of Oil Leakage and Thoroughly Clean the Intake System: Since a bad PCV valve causes oil leakage and buildup, it is wise to inspect the intake system, valve cover, and turbocharger for any signs of oil contamination. Cleaning of these areas can help to avoid further problems after the valve has been replaced.
- Replace Hoses and Connections: The hoses that connect the PCV valve to the engine can easily become brittle or clogged. If the hoses are faulty or restricted in any way, then they should be replaced to allow proper air flow.
- Engine Adaptations: If the crankcase ventilation valve needs to be changed, then it may also be necessary to set the engine adaptations using a diagnostic tool. This helps the engine control module to learn the correct air fuel ratio and idle position to enable proper running of the engine.
Make Your Next BMW Engine Service Appointment With Us Now
At Heynneman European, 
we are the top shop to visit for BMW repairs and maintenance services, including diagnosing and repairing crankcase ventilation valve issues. We have professional, experienced technicians with state-of-the-art techniques to identify the root cause of the problem and offer excellent services to fix it. We have been catering to BMW car owners in San Rafael, CA since 1979, and proudly welcome drivers from our surrounding neighborhoods. If you are having issues such as rough idle, blue smoke, or high oil consumption in your BMW, then consider visiting our shop. We will ensure your BMW is up and running as it was when it was brand new. Contact us now to get superior service for your luxury vehicle.
* Grey BMW M5 Car image credit goes to: Brandon Woyshnis.
