Back to all

The Little Valve that Could (PCV Valve Replacement)

May 5, 2024

It's easy to get letters like PVC and PCV mixed up.  PVC is a plastic that's used in a lot of things, especially plumbing pipes.  And PCV is a valve that helps your engine burn off excess fumes rather than having them pollute our atmosphere. 

PCV stands for positive crankcase ventilation.  When your engine ignites gasoline in the cylinders, some of the gases produced make their way into the crankcase, where oil is held to lubricate the engine.  In earlier days, those gases would be vented out through a hose and go directly into the air.  It was a waste of gasoline (since about three-fourths of the gases were unburned fuel) and a nasty source of pollution.

So engineers devised a one-way valve that directed those gases back into the engine's air intake system to be burned again.  After a while, the PCV valve can get clogged up with gummy oil.  Not only does that reduce the recirculation of the gases, but it can also cause pressure in the crankcase to increase and possibly lead to an oil leak.

Signs your PCV valve has failed are oil leaks around the engine compartment or under your vehicle and poor engine performance. Your fuel economy will get worse. If you notice those signs, we can check your PCV valve. 

At the same time a technician inspects the PCV valve, they'll also check the vacuum hose that runs back to the air intake.  Plus, they'll make sure the vehicle doesn't have any other engine problems that might be contributing to your issues. 

Many technicians recommend replacing your PCV valve with each major tune-up, so you get ahead of any problems before they develop.  Now that you're an expert on PCV, it may be time to check out those PVC pipes in your bathroom!

Tuffy Chicago (Diversey Pkwy)
1400 West Diversey Pkwy
Chicago, Illinois 60614
773-929-3622

More articles from Tuffy Chicago

Why Maintaining Your Windshield Wipers and Washers Matters (Windshield Wiper and Washer Inspection)

January 18, 2026

What do mud, bird droppings and frost all have in common? When theyre covering your windshield, they can temporarily obscure your view of the road, leaving you driving blind. And when you cant see the road clearly ahead of you, it can be really scary. Thats one of the reasons its important to m... More

Tuffy Chicago (Diversey Pkwy) Service Tip: Why Synthetic Oil Is Good For Your Vehicles

January 11, 2026

Hello Illinois! Today's vehicle care topic is: Synthetic Oil vs. Petroleum Based Oil. Synthetic motor oil is a substitute for petroleum based oil. If you aren't currently using it, why not? Synthetic motor oil maximizes engine power and fuel economy. To see why, we'd need a microscope, so we'll ... More

Don?t Blow Your Cool (Water Pump Replacement)

January 4, 2026

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