How does a Subaru PCV valve work?

How a Subaru PCV Valve Works
The Positive Crankcase Ventilation (PCV) valve in a Subaru is a crucial component of the engine’s emissions control system. It regulates the pressure and airflow in the engine, allowing it to breathe and removing harmful oil vapors from being released into the atmosphere.
Function of the PCV Valve:
The PCV valve transfers gases from inside the crankcase to the intake manifold, where they are burned as part of the normal combustion process. Excess fumes are burned by the engine, rather than released into the atmosphere. When excess gas accumulates in the crankcase, the PCV valve redirects it through the intake manifold, where it is used as a normal part of the engine’s process.
Checking the PCV Valve:
To check if the PCV valve is functioning properly, it can be removed and shaken. It should jiggle freely internally. If the valve is stuck closed, it can cause issues such as a minor oil leak or even more severe problems like violent bunny hops and smoke coming out of the rear of the vehicle.
Symptoms of a Bad PCV Valve:
Understanding the symptoms of a bad PCV valve is important for vehicle maintenance. Some symptoms of a bad PCV valve include rough engine idle, decreased fuel efficiency, oil leaks, and increased oil consumption.
Replacement and Maintenance:
The PCV valve is relatively easy and cheap to replace, and it is recommended to inspect it regularly for any signs of being stuck open or clogged with sludge.
In summary, the PCV valve in a Subaru plays a crucial role in regulating the pressure and airflow in the engine, ensuring that harmful oil vapors are not released into the atmosphere and that the engine operates efficiently.
If you have any further questions about the PCV valve or any other automotive-related inquiries, feel free to ask!

How does a Subaru PCV work?

PCV stands for positive crankcase ventilation, when the pressure inside the engine is too high this valve opens and allows the pressure to be transferred to the intake tract. Given the engine crankcase is full of oil when the valve opens it can/will allow oil to flow through this valve.

What is the lifespan of a PCV valve?

between 20,000 and 50,000
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. Similar to 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.

Can you run a motor without a PCV valve?

Can you drive a car with a bad PCV valve? You can. The only effect it has is that you will consume more oil. It is there to allow the intake to create a small vacuum in the engine so that the piston rings can clean the oil off the wall better.

What is the problem with the PCV valve on a Subaru?

The PCV valve can get stuck open or clogged with sludge and should be inspected regularly and replaced when required. If the PCV valve is failing it can cause your Subaru’s engine to run rough and you may notice some exhaust smoke and oil leaks.

Will a bad PCV valve throw a code?

If the device detects a problem with the PCV system, it will turn on the check engine light and store a corresponding diagnostic trouble code in memory. A stuck-open PCV valve can also disrupt the air-fuel mixture and cause misfires that trigger the check engine light.

When should I replace my Subaru PCV valve?

Unlike changing your battery or oil, there is no particular time frame to replace your PCV valve. As long as a PCV valve is functioning properly, you do not need to replace it. However, they are subject to damage due to a lot of blow-by gases traveling through them which can sludge the valve up.

How do I know if my Subaru PCV valve is bad?

One very common sign of a bad PCV valve is a whistling or hissing sound coming from the engine. This can indicate that there is a slight blockage in the PCV valve. A Check Engine warning light can be another sign that you need to replace a PCV valve because the PCV valve impacts vehicle performance and emissions.

Can I run my car without PCV valve?

Not only does it allow waste gasses from the combustion process to escape directly into the atmosphere, but the lack of a PCV valve can cause permanent engine damage by interfering with the engine’s intended combustion process.

How is a PCV valve supposed to work?

The PCV valve regulates how much vacuum can pull through the crankcase. It’s hooked into the intake – when the vacuum is high at idle, the PCV valve stops most of that vacuum. As vacuum drops with an increase in RPM, The PCV valve opens, to allow a higher volume of gasses and pressure to be pulled into the intake.

What are symptoms of a bad PCV valve?

If the engine is difficult to start, idles roughly, misfires and is consuming more oil than usual, the PCV valve is jammed in the open position. When the engine surges and belches out black smoke or there’s an obvious oil leak or build-up of sludge inside the engine, the valve is stuck in the closed position.