What is a positive crankcase ventilation (PCV) valve?
A positive crankcase ventilation valve—known as a PCV valve for short—is a one-way valve that allows exhaust and unburned fuel to make its way out of the crankcase in your car’s engine and back into the intake manifold, where they can re-enter the combustion process.
The PCV valve helps reduce harmful emissions and plays a crucial role in ensuring that too much sludge doesn’t build up in the engine, which would lead to serious (and seriously expensive) damage.
When should I replace the positive crankcase ventilation (PCV) valve on my car?
You should replace a faulty PCV valve if you notice the following:
Illuminated check engine light
Hissing or whistling noises from the engine
Oil leaks (likely from blown engine seals or gaskets)
How often should a positive crankcase ventilation (PCV) valve be replaced?
Common replacement intervals can range from 20,000 to 50,000 miles, but you should check your owner’s manual to see if your vehicle’s maintenance intervals include a recommendation for PCV valve replacement.
Outside your vehicle manufacturer’s recommended replacement intervals, the only time you should need to replace the PCV valve is if it’s been prematurely damaged. Some PCV valves can develop clogs if enough oil or sludge builds up inside them.
Can I replace my positive crankcase ventilation (PCV) valve myself?
The process of replacing a PCV valve is simple overall, and some will find this to be a surprisingly quick and easy DIY car repair. That said, some vehicles’ PCV valves are more complicated or challenging to access than others.
If you don’t feel comfortable replacing a PCV valve yourself, you should have a professional mechanic take care of the job for you.