The crankcase ventilation valve belongs to the positive crankshaft ventilation (PCV) system in your BMW. It regulates the entry of the crankcase fumes into the intake manifold for combustion. This consequently leads to the reduction in pollution and prevention of build-up of sludge and corrosion inside the engine. The crankcase ventilation system is designed to handle a certain amount of gas and oil vapor; however, when the valve malfunctions, it can lead to problems in your BMW.

How to Spot A Malfunctioning Crankcase Valve

• Increased Oil Consumption: One of the earliest indicators of a malfunctioning CCV valve is an unusual increase in oil consumption. This happens when the CCV valve, which is supposed to recycle the oil vapor back into the engine for burning, fails. Instead of being reused, this oil vapor can escape, leading you to needing to add more oil to the engine more frequently than normal. If you notice that you’re filling up your oil more often, without any obvious leaks on the ground, your CCV valve might be responsible.
• Poor Engine Performance: Whenever there is a malfunction in your BMW’s crankcase valve, it can cause an imbalance which may later result in a mixture that’s too rich or too lean. This imbalance affects your BMW engine’s performance, manifesting as a rough idle where the engine feels like it’s shaking or hesitating when running. You might also notice lesser acceleration power and an overall reduction in your engine’s responsiveness. These symptoms are due to the engine not operating efficiently as the faulty CCV valve disrupts the proper ventilation of gasses.
• White Exhaust Smoke: Seeing white smoke emanating from your BMW’s exhaust is a more alarming sign of a CCV valve issue. This problem springs up when the failed valve allows oil to seep into the combustion chamber, where it gets burned along with the fuel. The burning oil produces white smoke, which is then expelled through the exhaust. It’s a clear indicator that the CCV system isn’t functioning as intended, leading to oil being misplaced and burned instead of being recycled back into the engine.

Dealing with a Malfunctioning Crankcase Valve

• Quick Diagnosis: The first step in addressing crankcase valve problems is to confirm that the component truly has an issue through a diagnosis. This mostly involves a visual inspection for any obvious signs of oil leakage or damage to the CCV system components. A mechanic may also perform a smoke test to check for vacuum leaks, which can indicate a cracked or broken CCV hose.
• Repair or Replace: Once a problem with the CCV system is confirmed, the next step is to decide whether to repair or replace the malfunctioning components. In many cases, replacing the entire CCV valve and its associated hoses is recommended, as these components can become brittle and fail over time due to exposure to engine heat.
• Choosing the Right Parts: When it’s time to replace your CCV valve, be sure to use high-quality replacement parts that are compatible with your BMW model. Opting for OEM (Original Equipment Manufacturer) parts is often the best choice for ensuring compatibility and reliability.

Should A Professional Handle This Problem Or Can You DIY?

Depending on your level of mechanical expertise, you might want to consider replacing the CCV valve yourself. Many BMW enthusiasts find this to be a manageable DIY project. However, given the complexity of BMW engine compartments and the importance of correct installation, it might be wise to entrust this job to a professional mechanic, especially if you are not confident in your mechanical skills.

Let Us Solve Your BMW Crankcase Ventilation Problems

At Kruse Lucas Imports, we have a crew of skilled BMW mechanics that you can count on, especially when it comes to sorting out those tricky crankcase ventilation problems. We have our garage in Modesto, CA, and we’re proud to be the go-to spot for drivers from neighboring cities like Manteca, Oakdale, Ripon, Turlock, and beyond. When you come to us, our mechanics will make sure your BMW runs like it’s new. Ready to get your ride feeling brand new? Don’t wait – book an appointment with us today and let’s get your BMW back to its best!

* Gray BMW X4 Car image credit goes to: Luca Piccini Basile.