What to Know About Failed PCV Valves in BMWs
BMW represents one of the top names in luxury vehicle manufacturers. The brand offers quality and classic designed in abundance. Sitting in a BMW often feels like the softest of chairs, allowing you to relax and focus on the joy of hitting the road. Driving a BMW is made all the more effortless through the variety of intelligent design features and systems that are often just a button press away.
However, some of the most crucial innovations often go entirely unnoticed by drivers. This can also mean they lack the proper care and maintenance that they deserve. Should they fail, they can result in a ruined driving experience or costly repairs. Therefore, in this article, we will take a closer look at your BMW’s PCV valve, learn about what it is, what it does, and most importantly, the signs of part failure.
What is the PCV valve?
The Positive Crankcase Ventilation valve, or PCV valve, was invented in the 1960s as a solution to a long-running motoring issue; blow-by gases. Blow-by gases occur when unburned fuel leaks from the engine. The blow-by gases are teeming with toxic and harmful substances, which if left alone can quite literally eat away at your vehicle’s insides.
The PCV valve is able to suck up the unburned fuel from the crankcase and redistribute it to the intake manifold, where it can be burned properly. It’s basically a fuel recycling plant right under your hood.
If this valve isn’t working properly, then the harmful blow-by gases are set free to do what we fear the most, destroy the inside of your vehicle, causing thousands of dollars of damage to your BMW, potentially even writing it off entirely.
How often should the PCV valve be replaced?
Typically, the valve itself won’t need to be replaced unless a problem occurs. However, inside the valve is a filter which does need monitoring and replacing. The PCV valve’s filter will most likely need to be changed at around 60,000 miles, with quality servicing in between each change to ensure everything is working properly. A quality mechanic will be able to monitor this part for you as part of your regular servicing and will replace it as needed.
The Signs of PCV Valve Failure
There are 2 key ways in which the PCV valve can develop issues and need replacement. The most common is the clogging of the filter. Less common is a failure of the valve mechanism itself.
Filter Failure Signs
• The internal engine pressure increases
• The seals or gaskets begin to fail
• Leaking engine oil
• Black smoke emitting from the vehicle
• Sludge build ups or deposits inside and around the engine
• Moisture or dampness under the hood
• Engine surges
• Lean engine misfires
• Oil deposits located in the MAF sensor
• An increased rate of oil consumption
Signs of a Stuck Valve
• A misfiring engine, most noticeable when idling
• A poor air-to-fuel ratio, which can lead to the aforementioned misfires
• Engine oil found in the valve itself
• An increase in oil consumption
• An engine that is tricky to ignite
• Idling that feels rough or juddery
Getting the PCV Valve Repaired or Replaced
As you can see the PCV valve is a simple part with an essential role to play. It should be treated with the care and respect it deserves or the results can be truly catastrophic. 
Unless you have mechanical experience, repairs and replacements should never be undertaken at home. Professional servicing for this part is very affordable. Filter and valve replacements can cost as little as $100 or less, barring any mechanical issues found by your mechanic.
For PCV valve servicing and repairs and all other care that your BMW needs, look no further than Munich West. We are situated perfectly for BMW drivers of the Decatur, Atlanta, GA areas. The mechanics at Munich West are experts in European cars, with over 40 years of experience and expertise. With an impressive 2-years/24,000 mile warranty, a variety of special offers and discount coupons, and consistent five-star reviews from satisfied and returning customers, when it comes to high-quality auto repair that you can trust, you should make Munich West your only pit stop.
* BMW F26 X4 image credit goes to: DarthArt.
