What does the PCV valve do on a Subaru?
The Positive Crankcase Ventilation (PCV) valve is a crucial component in your Subaru's engine system. It plays a significant role in maintaining engine efficiency and longevity. In this article, we will explore what the PCV valve does, why it is important, and how to recognize signs of a failing valve.
What is the PCV Valve?
The PCV valve is a one-way valve that regulates the flow of gases from the crankcase to the intake manifold. It is part of the vehicle's emissions control system, designed to reduce harmful emissions and improve fuel efficiency. By allowing gases that accumulate in the crankcase to be recirculated into the engine for combustion, the PCV valve helps to minimize the release of pollutants into the atmosphere.
Functions of the PCV Valve
The PCV valve serves several essential functions in your Subaru:
- Emissions Control: It helps reduce harmful emissions by recirculating unburned fuel vapors back into the combustion chamber.
- Engine Efficiency: By preventing the buildup of pressure in the crankcase, the PCV valve ensures that the engine operates smoothly and efficiently.
- Oil Contamination Prevention: It helps to minimize oil contamination by reducing the amount of moisture and fuel that can accumulate in the crankcase.
Signs of a Failing PCV Valve
A malfunctioning PCV valve can lead to various engine issues. Here are some common signs that your Subaru's PCV valve may need attention:
- Increased Oil Consumption: If you notice that your engine is consuming more oil than usual, it could be a sign of a failing PCV valve.
- Rough Idle: A faulty PCV valve can cause irregular engine idling, leading to a rough driving experience.
- Check Engine Light: If the check engine light illuminates on your dashboard, it may indicate an issue with the PCV system.
- Oil Leaks: Excessive pressure in the crankcase due to a malfunctioning PCV valve can lead to oil leaks.
Conclusion
In summary, the PCV valve is a vital component of your Subaru's engine that helps maintain efficiency and reduce emissions. Regular maintenance and timely replacement of a failing PCV valve can prevent more significant engine issues down the line. If you suspect that your PCV valve may be malfunctioning, it's essential to consult with a professional mechanic to ensure your vehicle remains in optimal condition.
Frequently Asked Questions
What code will a bad PCV valve throw?
For instance, a PCV valve that sticks open may cause a check engine light. The diagnostic trouble codes or DTC will normally not mention the PCV valve. Instead, the diagnostic trouble code P0171 and P0174 are common. These codes suggest a lean-condition in the engine.
What will replacing the PCV valve do?
What Are the Benefits to Replacing My PCV Valves? Reduce Oil Consumption: Helps reduce oil consumption. Removes Moisture: Removes damaging moisture from the oil. Reduce Crank Pressure: Helps eliminate excessive crankcase pressure from forming.
Can you still drive with a bad PCV valve?
It's not advisable to drive with a bad PCV valve because it can cause the gaskets to blow.
How often should a Subaru PCV valve be replaced?
Subaru recommends changing the valve every 30k miles as routine maintenance which a shop will charge you over $200 for!
How often should a PCV valve be replaced?
There isn't a specific lifespan for a PCV valve, but you can usually plan to replace it anywhere between 20,000 and 50,000 of driving. Like many other parts of your car, regular maintenance will extend the life of your PCV valve, while neglecting regular oil changes and signs of trouble will shorten it.
How much should it cost to replace a PCV valve?
The average cost for a PCV valve replacement is $186 to $220.
What happens when the PCV valve goes bad?
Engine Performance Issues: A bad PCV valve can affect the air-to-fuel ratio, potentially causing rough idling, poor acceleration, or reduced fuel efficiency. Emissions Problems: A defective PCV valve can lead to increased emissions, which might cause your vehicle to fail emissions tests.
How do I know if my Subaru PCV valve is bad?
If it the PCV valve is stuck open, the presence of smoke would correlate with high manifold vacuum such as when idling or engine braking. If your PCV rattles when you shake it, and there's no oil in your PCV hose (both signs of good PCV valve) that could mean bad valve seals and/or guides.
Is it OK to drive with a bad PCV valve?
It's not advisable to drive with a bad PCV valve because it can cause the gaskets to blow.
How much does it cost to replace a PCV valve?
The average cost for a PCV valve replacement is $186 to $220.
