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PCV Valve Replacement

How to Replace the PCV Valve on a 4.6L/5.4L F-150


As a result of blow-by, gasoline fumes enter the crankcase of your engine during the compression stroke. If not properly ventilated, these fumes will contaminate your engine oil. Since gasoline is a solvent, fuel contaminated oil does not provide proper engine lubrication, causing excessive engine wear. A PCV (positive crankcase ventilation) valve is essentially a check valve that allows these fumes to be removed from the crankcase, limiting oil contamination. Instead of venting gases from the crankcase into the atmosphere, the PCV valve diverts these gases into the engine's intake system so they can be consumed. Over time, oil and fuel fumes gunk up the PCV valve. Symptons of a faulty PCV valve include poor/rough idle, engine hesitation, loss of responsiveness, loss of acceleration, fuel in oil, and decreased in fuel economy.


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• Locate the PCV valve. On this 4.6L 2v Triton V8, the PCV valve is located on the passenger side valve cover. Some 5.4L 3V V8s have the valve located on the driver side valve cover. The location is not universal for all 4.6L/5.4L V8 engines; the style and location can be different depending on the model year. If you have trouble locating it, look at the replacement and use it to find the PCV valve on your engine.

• Remove the hose coming out of the top of the PCV valve. On some engines, the hose may have a hose clamp that will need to be loosened to allow removal of the hose. On others, the hose will not be clamped and can be pulled off with a light tug. Some models have heated PCV valves, so you will also need to carefully remove the wiring harness attached to the valve.

• Using the properly sized wrench (or a cesent wrench), remove the PCV valve by turning it counter clockwise. Some PCV valves will be held in by 2 small bolts (5.4L 3v engines, for example). Remove the bolts and pull the valve out. Other engines will have PCV valves that just slip into place. Using your hand, or pliers if necessary, carefully remove the valve.

• If the valve is threaded, install the new PCV valve by threading it into the valve cover, by hand first, and seating it with a wrench. Do not overtighten - the valve simply needs to be seated securely in location. Do not use pliers on this type of valve as you risk damaging it.

• If the PCV valve is not threaded, slip it securely into place. Re-install and tighten the bolts that hold it in place, if applicable.

• Reinstall the hose, hose clamp(s) (if applicable), and wiring harness (if applicable).