PCV Valve: What Is It?
April 17, 2018
Most Clawson 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. Clawson 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 Top Tech Auto Repair Clawson.
The PCV system reduces harmful vehicle emissions. The maintenance it requires is simple and inexpensive at Top Tech Auto Repair Clawson. A fouled or damaged PCV system can lead to serious engine damage for Clawson drivers.
Let's all learn to practice good car care. It's good for our wallets, and it's good for our Michigan environment.
Top Tech Auto Repair Clawson
664 S Rochester Rd
Clawson, Michigan 48017
248-589-0980
http://www.toptechautorepairclawson.com
Need Service?
More articles from Top Tech Auto Repair Clawson

Don?t Blow Your Cool (Water Pump Replacement)
October 12, 2025
Its always a good idea to keep your cool, and thats especially true when it comes to some components of your vehicle. One is the engine. Its hot under that hood thanks to the mini explosions that are occurring in the internal combustion engine when its running. Your vehicle has a cooling syste... More

Gearing Up (Differential Fluid Service)
October 5, 2025
You may have never thought about it, but when you turn a corner, the wheels on one side of your vehicle turn at a different speed than the other side. What is this magic? The answer is something called the differential. A differential is a gear box placed between the drive wheels and needs lub... More

Making Sense of the O2 Sensor (Oxygen Sensor Replacement)
September 28, 2025
As you know, todays vehicles rely on a lot of computers in them to keep them running clean and efficiently. Those computers depend on information delivered by several sensors throughout the engine and exhaust system. And one of the most important is the oxygen sensor. Known as the O2 sensor f... More