Simple how to: Replace the PCV valve, PCV hose, and oil/air separator on Ford Duratec and Mazda L / LF I4 engines.
Positive crankcase ventilation components are often given insufficient maintenance attention. Valves can clog up and vacuum hoses often rupture or collapse. A split hose is a common cause of vacuum leaks on these engines.
These PCV parts are between the engine and intake manifold, so require removing the manifold – see here: https://youtu.be/vBxm5QjD0PY
Search Amazon for parts*:
Ford, US: http://amzn.to/2dekKBt | UK: http://amzn.to/2duAGxq
Mazda, US: http://amzn.to/2cI6ZrI | UK: http://amzn.to/2dewgAk
* The car shown is a 2002 Mondeo but the Duratec and Mazda L/F engines all use the same design. Parts vary and in many cases were revised with improved designs, as touched on in the video. In my case for example, renewing the intake manifold itself would require upgrading all components through to the oil separator.
(Using the above Amazon links helps support my channel and is appreciated!)