Back to all

The Little Valve that Could (PCV Valve Replacement)

July 13, 2025

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 Tire & Auto Service Plainfield
23846 W 135th St
Plainfield, Illinois 60544
815-436-1337

More articles from Tuffy Plainfield

Cabin Air Filter and Engine Air Filter: What?s the Difference?

October 12, 2025

You may have heard someone say they just got the air filter replaced in their vehicle. But did you know your vehicle has two different major air filters and they both perform quite differentbut very importantduties? Todays vehicles have a cabin air filter, and an engine air filter. The engine a... More

Timing is Everything (Timing Cover Replacement)

October 5, 2025

Theres an important part in your vehicle that shields your timing belt, timing chain or cam belt from the debris and gunk that can be kicked up from the road. Its called the timing cover. Its important because the timing belt or chain is what coordinates parts of your engine called the camshaft... More

Don't be Fuelish (Signs Fuel Pump is Failing)

September 28, 2025

A driver of a large SUV loaded with equipment was heading on a 7-hour work trip when he stopped at a gas station to refuel. When he went to restart his SUV, it turned over but wouldn't catch. Try as he might, he was never able to get it started again. Of course there are many things that can c... More