PCV Valve

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    1-24 of 249 Results

    About PCV Valve

    Whistling, whining, or moaning noises can be a good sign that's time to replace your PCV valve. If you're experiencing these symptoms, turn to AutoZone. We carry reliable replacement parts from brands like ACDelco, AZ Filters, and Dorman. Restore your engine's performance fast with free next day delivery on AutoZone.com, or pick up your parts in a store near you today.

    Bad PCV valve symptoms depend on whether the valve is stuck in the open or closed position. A PCV valve that is stuck open can cause oil leaks from the failure of oil seals or gaskets, sludge buildup in the engine, and an increase in engine pressure. Symptoms of a clogged PCV valve include lean air fuel mixture, increased oil consumption, and rough idling. These symptoms indicate it’s time to replace the valve.

    AutoZone makes finding the right PCV valve for your vehicle easy. Just enter your vehicle's year, make, model, and engine at the top of this page, and we'll find the perfect fit.

    PCV stands for positive crankcase ventilation. The valve is an integral part of the crankcase ventilation system (CVS), responsible for controlling the flow of combustion fumes in the internal combustion engine's crankcase. See, when your engine's spark plugs ignite the air-fuel mixture that is fed into your engine cylinders by the intake manifold, some of the combustion fumes escape into the crankcase, where your vehicle's crankshaft is rotated by the moving cylinders. These fumes are sometimes called blow-by gases, because they blow-by the piston rings, which prevent most fumes from entering the crankcase.

    Back in the day, these fumes would freely circulate in the crankcase before being exhausted with the rest of a vehicle's emissions. As a result oil was nearly always leaking and being contaminated by the blow-by gases, causing decreased efficiency and more frequent oil changes. Some vehicles used a road draft tube, an early attempt at ventilating the crankcase. It was effective in many situations, but depended on drafts of air created by the movement of the vehicle. This meant that slow moving vehicles or delivery trucks that frequently let their engine idle did not get much out with the tube. Tank operations in World War II ran into this same problem, prompting the invention of PCV Valves.

    In addition to boosting efficiency, researchers found that blow-by gases from the road draft tube were a major source of smog-causing pollution, prompting the installation of the PCV valve in modern automobiles around 1964.

    The PCV valve works by recirculating blow-by gases in the crankcase back to the intake manifold. Positive crankcase ventilation boosts efficiency while reducing emissions because the recirculated fumes are able to be combusted again, leading to more efficient fuel use. At idle and low speeds, there is greater air pressure in the crankcase than the intake manifold, allowing the PCV valve to vent air from the crankcase to the intake manifold.

    If your car has a problem in the PCV valve, get the parts you need with free next day delivery or same day in-store pickup, so you can remove the valve and install a working replacement quickly.