The Best Repair Shop in Bellevue to Repair a Malfunctioning PCV Valve in a BMW


When you think about your BMW’s maintenance, the PCV valve probably isn’t the first thing that comes to mind. However, it is a very important component of your vehicle’s engine and helps keep your BMW running smoothly. If your vehicle is running sluggish or backfires are occurring more frequently, a failing PCV valve might be to blame.

The PCV valve is part of the PCV system and is responsible for allowing waste gases to escape the crankcase and enter your engine to mix with fuel and be burned, instead of released into the atmosphere. This permits cleaner oil and exhaust in your BMW and allows the engine to run more efficiently.

In 1970, Congress passed new emissions regulations and gave the EPA control to regulate pollution caused by transportation, including commercial vehicles. Although invented in the 1960s, the PCV valve has since been more widely seen in vehicles for purposes of emissions control.

How the PCV Valve Functions

PCV is an acronym for Positive Crankcase Ventilation. The crankcase holds your vehicle’s motor oil and is located at the bottom of the engine. When your engine burns the fuel that powers your vehicle, combustion gases, also called blow-by, are produced. Typically, these blow-by gases exit the vehicle through the exhaust system, but a portion of the gases push down through the pistons and into the crankcase.

The PCV valve is a small, one-way valve attached to the crankcase, and allows blow-by gases to exit the crankcase through the intake manifold. Once the gases enter the intake manifold, they are routed back into the engine to mix with fuel and be burned. This essentially recycles the blow-by gases. If not for the PCV valve, gases would exit through the exhaust system into the atmosphere and pollute the environment.

The PCV valve also functions to remove pressure from the crankcase. As blow-by gases leak into your vehicle’s crankcase, pressure is created and can cause damage to your engine if too much pressure is accumulated.

Signs Your PCV Valve is Malfunctioning

If your BMW has a faulty PCV valve, the overall performance of your vehicle will start to decline, including slowed acceleration, excessive fuel consumption, and oil leaks.

  • Oil sludge: Since the PCV system releases gas from the crankcase, without it those gases will remain and mix with the oil in the crankcase to produce oil sludge. Built up sludge will corrode the engine and gum up its various passages.
  • Oil leak: A clogged or closed PCV valve can fail to release mounting pressure in the crankcase causing oil leaks. This happens because the pressure in the crankcase pushes oil out through its seals and gaskets, causing it to drip out onto the floor of your garage or driveway. If you notice an oil puddle, the PCV valve may be malfunctioning.
  • Increased fuel consumption and emissions: If your PCV valve is failing to release blow-by gases into the vehicle’s fuel supply, fuel consumption will increase because it does not have the gases to mix with. This will also create more emissions from your vehicle’s exhaust.
  • Decreased acceleration: If instead the PCV valve is stuck open, too much air and gases can mix into the fuel. This air-heavy mixture can lead to backfires, lagging acceleration, and make it hard to start your vehicle.

Landmark Motors for your BMW

If you find your BMW’s PCV valve isn’t functioning correctly, a replacement may be in order. Landmark Motors can quickly handle this and all of your BMW needs.

Landmark Motors is Bellevue’s leading European auto service center and repair shop. Our expert mechanics and technicians use state-of-the-art facilities and equipment to test your BMW’s PCV valve for air flow problems. We will determine what steps need to be taken to get your vehicle on the road safely and running smoothly again.

BMW PCV Valve Check

The longevity of your BMW is our top priority. We specialize in European-made vehicles and provide high quality service from routine maintenance to emergency repairs, all at a fair price. A dealership repair quote can be sky-high, but Landmark Motors provides quality service for a fraction of the price of a dealership.

Landmark Motors proudly serves the Seattle and Bellevue, WA, area and is ready to service your BMW and answer any questions you may have. Call our expert staff today or easily schedule an appointment online.

* BMW Car image credit goes to: D. Lentz.