Buy Ford Mustang PCV Valves

Positive crankcase ventilation (PCV) became standard on U.S. cars in the early 1960s to curb smog. It draws fumes out of the crankcase through a spring-loaded valve that closes under boost or backfire. (Wikipedia) The U.S. Environmental Protection Agency notes that eliminating crankcase venting slashes hydrocarbon emissions. (EPA NPDES) In the Mustang, the valve typically sits in a valve-cover grommet and connects by hose to the intake manifold, providing constant airflow while shielding the engine from dirt. (Mustang6G) See the EPA overview of crankcase controls for a deeper dive.

• Location by generation - Many 1996-2018 V-8 and V-6 Mustangs place the valve on the passenger-side valve cover; earlier 5.0-liter models mount it at the rear of the lower intake, and modern 5.0 "Coyote" engines use a screw-in style on the driver's-side cover. (AmericanMuscle.com)
• Catch-can upgrades - Owners often add an oil-air separator (catch can) in the PCV hose to keep oily mist from coating the throttle body or intercooler, especially on boosted EcoBoost or supercharged GT builds. (Mustang7G)
• Service interval - Ford owner's manuals advise checking the valve around every 30,000 miles or sooner if idle quality changes. (Ford Service Content)
• Emissions link - A working PCV system is part of the federal OBD-II readiness check; a failed valve can set lean-condition codes such as P0171/P0174. (YouTube)

A failing valve may whistle, stick, or crack. Common symptoms include rough idle or stalling, oil leaks at seals, burned-oil smell, elevated oil consumption, milky sludge under the filler cap, and illuminated check-engine light. (RepairPal.com) Forums also report vacuum at the oil-cap hole disappearing when the valve sticks. (Bob Is The Oil Guy) Mechanics warn that ignoring these clues can starve the engine of lubrication and cause severe damage. (The Sun)

• Rattle test - Remove the valve and shake it; a good valve rattles freely. (RepairPal.com)
• Thumb test - With the engine idling, remove the breather side hose and cover the opening; there should be a slight vacuum, not pressure. (Bob Is The Oil Guy)
• Smoke test - A shop can apply low-pressure smoke to find leaks in PCV hoses or diaphragms. (RepairPal.com)

Most valves cost under $40 and take 10-20 minutes to swap with basic hand tools. (RepairPal.com) On 2015-up GT models, press down and twist counter-clockwise to release the threaded valve; older 5.0 pushrods simply pop out of the grommet. (Mustang6G) Always inspect and replace the rubber grommet or O-ring if cracked, and clear any mesh filter under the valve on 1979-95 cars. (Mustang Forums at StangNet)

Check for vacuum leaks and clean hoses at every oil change. Replace the valve every 30k-50k miles or if any failure signs appear. (Ford Service Content) Turbo and track-driven Mustangs may need shorter intervals because of higher crankcase pressure. (Mustang7G)

The PCV system cuts hydrocarbon emissions by burning blow-by gases instead of venting them. (EPA NPDES) Studies show disabled systems can raise crankcase emissions by over 50 percent. (EPA NPDES) Keeping the valve healthy helps your Mustang pass inspections while protecting the planet.

DIY replacement costs about $10-$40 for the part and under half an hour of labor; a shop may charge $110-$155 including parts. (RepairPal.com) Neglecting it can lead to oil leaks, catalytic-converter fouling, or engine rebuilds that cost thousands. (The Sun)

Performance owners often add baffled catch cans or dual-breather setups to the PCV circuit to trap oil mist and keep intake runners clean, especially on boosted engines. (Mustang7G) High-RPM track cars may also run larger-orifice racing valves to handle extra blow-by, but these should be paired with custom tuning to avoid a lean mix. (YouTube)

Q: What does the PCV valve do in simple terms?
A: It acts like a tiny door that lets dirty gases leave the engine, so they can be burned again. This keeps the oil clean, stops pressure build-up, and reduces air pollution. (Wikipedia)

Q: Where is the PCV valve on my Mustang?
A: On most 1996-2018 models it's in the passenger-side valve cover; on classic 5.0 pushrod engines it sits at the rear of the lower intake; on 2015-up 5.0 engines it screws into the driver's-side cover. (AmericanMuscle.com)

Q: How can I tell if mine is bad?
A: Look for rough idle, oil leaks, higher oil use, or a whistling sound. Shake the valve-no rattle means it's clogged. (RepairPal.com)

Q: Will a bad PCV valve trigger a check-engine light?
A: Yes. It can set lean-condition codes like P0171 or fuel-trim codes when too much un-metered air enters the intake. (YouTube)

Q: Can I clean the valve instead of replacing it?
A: You can spray carb cleaner through it if it still rattles, but replacement is cheap and quicker if the valve is stuck or cracked. (Car Talk Community)

Q: How often should I change it?
A: Inspect every oil change and replace about every 30k-50k miles, or sooner on high-boost or track cars. (Ford Service Content)

Q: What tools do I need?
A: Usually just pliers, a flat-head screwdriver, and perhaps channel-lock pliers for the threaded Coyote valve. (Mustang6G)

Q: Do I need to unhook the battery?
A: It's not required, but disconnecting the negative cable can clear old codes and add safety if you're reaching near the starter wiring. (Ford Service Content)

Q: Will adding a catch can void my warranty?
A: A catch can that installs in-line and is removed for dealer visits seldom causes warranty issues, but keep original hoses to reinstall if needed. (Mustang7G)

Q: Can a bad valve cause sludge?
A: Yes. If crankcase gases stay trapped, moisture and fuel dilute the oil and form a milky sludge under the filler cap. (Wikipedia)

Q: How does the PCV system help the environment?
A: It recycles unburned fuel vapors instead of venting them, cutting hydrocarbon smog and keeping streets cleaner. (EPA NPDES)

Keeping your PCV (crankcase) valve fresh is one of the simplest, cheapest ways to protect your Ford Mustang's engine, save fuel, and keep the air cleaner for everyone.