How to: Replace PCV valve, hose, oil separator Ford Duratec / Mazda L (Focus/Ranger/Mondeo/Mazda)

How to: Replace PCV valve, hose, oil separator Ford Duratec / Mazda L (Focus/Ranger/Mondeo/Mazda)

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:

Search Amazon for parts*:
Ford, US: | UK:
Mazda, US: | UK:

* 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!)



Craig's DIY Car says:

Search Amazon for parts*:
Ford, US: | UK:
Mazda, US: | UK:
See description for more info

Jonathan A says:

The 1.8, 2.0, 2.3 and 2.5 are all Mazda engines, just assembled by Ford. Here in the US, I have the 2.5 in my Ford Fusion. Same process to replace the pcv valve. I have 166,000 miles and I think it's time to change it.

Ken Hopp says:

Thanks for your video
You helped me greatly

Conzy Eíre says:

Hello Craig to your knowledge is this the sane engine as a 2005- 1.8 volvo s40? And if so do you think the pcv valve from ford will fit? Thanks Alot.

Renato Poli D'Amario says:

Hi Craig, greetings from Brazil!
I have a problem with my Focus MK2,5 2.0L Duratec Petrol. The issue is that I'm getting oil on the spark plugs of cylinders #3 and #4.
I'll check about valve leaking and cylinder's rings leak but I would like to know if the oil on the spark plugs could be caused by a bad PCV valve or hose?
There is no valve's cover leak.
Thanks in advance.

S-tech says:

Great video and horrible designed car

bjorn Becker says:

can anyone help me find these parts including the hose? I'm in the Netherlands and I cant find these parts anyware. I prefer not to go to the local ford dealer here since they broke my lock bolt and damaged 2 of my rims and they don't want to replace them.

R S says:

Is there a way to check if the valve is stuck without dismantling anything but a hose in which i can suck or blow to ear there a click sound from the valve ? Thanks ! Engine : Duratec ST (Fiesta ST 150)

Camilo Nuevo says:

Wish I knew it 2 weeks ago

Matt Santos says:

I heard that the pcv valve can be changed from underneath the car with long bent needle nose pliers… It's difficult but possible apparently without having to take the intake manifold off. I think mine it causing my excess oil burning problem…. I just hope that I will be able to change it without taking off the manifold.

eddyemm says:

Pcv hose is cracked but not leaking oil. Could be causing problems.

eddyemm says:

Same for Ford Galaxy owners also. Thanks for the upload. Now to take off the oil separator and check inside there as the engine is burning oil. My pcv valve rattles freely and compression through a compression tester is even on all cylinders. There is black sludge sitting on top of the pistons. Going to pour paraffin into the cylinders to clean it away and then change oil just in case piston rings are sticking. Hope it sorts it out or I'll be taking it to a garage to get valve seats looked at otherwise. Thanks.

Yankee Quintana says:

great video, thanks for full info about this car…

Albert Vaca says:

nice thanks

CopperFiremist says:

Man I just did this job without taking the intake off PITA…. removing the intake is probably the quicker and better option! Try and use a Motorcraft hose the dorman made in china hose is a tad shorter.


Hello, mondeo 3 has got idle speed increase especially after engine warm up, I changed the idle valve and potentiometer again! I think the manifold flaps are making noise. I would like information if you have experience with this fault.

Martin Szewczyk says:

Can I replace it when any black hose with the same length or does it have to be a certain material etc

Jay G says:

i guess im lucky, i have a 2.3 liter duratec on an escape and the pcv valve and hose are at the back and easily accessible

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