How to Fix a PCV Valve Failure in Your BMW by a Certified Thousand Oaks Mechanic
By Bavarian Performance Specialists March 1, 2021
The PCV valve was invented to deal with toxic vapors left behind in your engine after it burns through fuel. These vapors are known to be able to cause tremendous damage to your BMW’s engine if left to circulate through it. If they are not specifically released from the engine compartment, rapid corrosion will occur.
On the flip side, these toxic gases should not be released into the environment either. The PCV valve is the solution. It utilizes the vapors and recycles them to get more performance out of your BMW’s engine. So, when it stops working properly, it can cause major problems for your engine’s mechanical parts and for your horsepower.
What is a PCV valve?
The Positive Crankcase Ventilation (PCV) valve was created to solve a common problem for auto manufacturers with the issue of blow-by gases. These blow-by gases are toxic fumes created by the engine during its combustion cycle and are mostly unburned fuel vapors.
Blow-by gases are highly corrosive to your engine’s components, so the PCV valve was created to prevent this from occurring. This innovative valve is situated under the hood of your BMW. The valve opens and closes to allow your engine to “breathe” and reroute blow-by gases away from the crankcase through the intake manifold. The valve recycles the vapors back through the engine, where the fumes can be burned again without corroding the engine.
If this important valve begins to fail, these toxic fumes will remain inside your vehicle’s crankcase, causing your engine to be corroded by toxins.
Replacing a PCV Valve or Its Filter
The PCV valve can develop issues by becoming stuck open or closed. However, a more likely scenario deals with the filter for the PCV valve. Filters are designed to catch debris such as road dirt, grime, leaves, and particles that constantly bombard your BMW while it’s on the move. The PCV valve filter is no different, but it captures the toxic vapors in the stream of gasoline. Naturally, this filter can get clogged the more it is utilized to capture debris and keep it out of the valve.
Your manufacturer recommends that your BMW’s PCV valve filter be replaced every 60,000 miles or less if needed. Routine maintenance includes a check of your PCV valve filter, so if you are on a regular service plan, your BMW mechanic will check your filter as part of your inspections. They will advise you if it becomes necessary to replace your filter before the recommended mileage mark.
Common Signs of PCV Valve Filter Failure
There are some common signs of PCV valve filter failure. These symptoms include increased consumption of oil or oil leaking from the engine. Both of these will trigger a dashboard warning light, so be sure to keep an eye on your indicators. You may notice a rise in the engine pressure or feel a surge in your engine. There may be a seal or gasket failure or oil found in your MAF sensor, which will trigger a check engine light. There may be black smoke from your exhaust or you can see wetness under your hood on the ground. Last, your engine can misfire. This is an obvious sign of a problem which should be inspected by your trusted BMW mechanic.
Is the problem your PCV valve or the MAF sensor?
Your MAF sensor can malfunction and create many of the same signs in your BMW as a PCV valve failure. These include engine misfires while idling, lean or rich, along with increased oil consumption, and problems with your ignition. Talk with your mechanic to determine if the problems you are having are the MAF sensor or the PCV valve.
Professional Help for PCV Valve Replacement
At Bavarian Performance Specialist, we are proud to serve the residents of Thousand Oaks, CA and the surrounding communities. We are the leading auto repair service center for your BMW. We also are experts in other makes such as Audi, BMW, Mercedes, Porsche, & Volkswagen since 1983. Check out our customer reviews online to see why we are consistently chosen to care for your vehicle. Call us today to set up a convenient appointment.