Back to all

PCV Valve: What Is It?

March 24, 2019

Most Oswego drivers know something about preventive maintenance on a vehicle. We know we should routinely replace the oil and wiper blades and other fluids. But have you heard of a PCV valve ? This little car part needs to be replaced regularly or it can cause some serious problems in your vehicle engine.

PCV stands for Positive Crankcase Ventilation. The crankcase holds your motor oil and is located at the bottom of your engine.

When fuel is burned in your engine, it produces waste gases that are mostly vented out through your exhaust system. But some of these gases push their way past the pistons and into the crankcase. There, these gases can mix with motor oil to produce oil sludge, which can damage vehicle engine parts through corrosion and by clogging engine passages. Oswego vehicle owners should be advised that if the engine is running at high speeds, these gases can also cause pressure inside the crankcase to build up. This pressure, in turn, can blow gaskets and damage seals, leading to oil leaks.

The waste gases that leave the engine are comprised of about 70% unburned fuel. They used to be vented off the crankcase into the atmosphere. But starting in 1964, laws mandated that these gases be recaptured. Manufacturers began installing PCV systems, which recycled the gases into the air intake system where they could be mixed with fuel and sent to the engine to be burned.

The PCV valve is a one-way valve attached to the crankcase. Waste gases exit the crankcase through the valve but cannot enter.

Over time, the waste gases leave deposits on the PCV valve that can gum it up. So it needs to be replaced occasionally. This is an inexpensive part of preventive maintenance that is often overlooked, but which can have very expensive consequences. It's good auto advice to keep this little valve clean and working well.

In order to maintain efficient circulation, the PCV system also has a breather tube that allows clean air to enter the crankcase. This air is usually filtered through the engine air filter. But some vehicles have a separate air filter for the breather tube called the breather element. If this is the case with your vehicle, proper maintenance of the PCV will include replacing this element. To find out whether your vehicle has this type of PCV system, check your owner's manual or ask your service advisor at Tuffy Tire & Auto Service Oswego.

The PCV system reduces harmful vehicle emissions. The maintenance it requires is simple and inexpensive at Tuffy Tire & Auto Service Oswego. A fouled or damaged PCV system can lead to serious engine damage for Oswego drivers.

Let's all learn to practice good car care. It's good for our wallets, and it's good for our Illinois environment.

Tuffy Tire & Auto Service Oswego
1555 US Highway 34
Oswego, Illinois 60543
630-898-6220

More articles from Tuffy Oswego

No Fueling! (Fuel Filler Location)

February 2, 2025

If you've ever gotten in an unfamiliar vehicle, maybe a rental car, you may have pulled up to the gas pump and wondered, "Which side is the fuel filler on?" Here's a tip for you. There is usually a little arrow on the instrument panel near the fuel gauge that points to the side where the fuel fi... More

Full Stop (Brake Master Cylinder Replacement)

January 26, 2025

When you step on your brake pedal, you want to feel confident that your vehicles going to stop. If your brakes arent working right, its a risk to your safety and the safety of others on the road. After all, youre driving a machine that weighs thousands of pounds, and you have to be able to stop... More

The Vivacious Vernal Vehicle (Preparing Vehicle for Spring)

January 19, 2025

Most of us look forward to spring because the days are longer, the weather's warmer and we can finally get our vehicles into warm weather mode. Here are a few things that will breathe fresh energy into anyone's car, SUV, truck or van. First thing is a good cleaning, especially underneath. If you... More