September 26, 2026 BY
IN Engine

What is the Positive Crankcase Ventilation (PCV) Valve all about?

The PCV Valve transfers gasses 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.

Keep in mind:

PCV valve failure can be caused by other engine problems. To ensure that this is not the case, a mechanic should test your engine after replacing the PCV valve, to make sure that the car runs well and doesn’t have other issues.

How it's done:

● Disconnect the vacuum hose.

● Remove and replace the PCV valve.

● Replace PCV hose if appropriate.

● Install vacuum hose.

Our recommendation:

In general, it is a good practice to replace the PCV valve during every major tune-up. Changing the engine oil and flushing the engine on a regular basis will prevent sludge build-up inside the oil pan that may cause the PCV valve to fail.

What common symptoms indicate you may need to replace the Positive Crankcase Ventilation (PCV) Valve?

● Leaks in the engine compartment.

● Leaks underneath the car.

● A hissing noise from the engine.

● Car runs poorly.

How important is this service?

As excess gas accumulates in your crankcase, the PCV valve redirects it through the intake manifold, where they are used as a normal part of your engine’s process. When the PCV valve fails, your engine won’t redirect this excess gas that it depends on. As such your vehicle will not run smoothly, and it will likely get much worse gas mileage.