I own a 1993 f-150 302 (5.0l), the engin was blowing oil out somewhere on the driver side i think from the dip stick so i changed the pvc valve thinking it was gone so when pressure built up thats where the oil could escape!! The oil stoped for a bit but now is doing the same thing! I dont know whats causeing it? Could it be valves or..? Any ideas guys

 

Engine is worn out and has exsessive crankcase pressure.

 

There 200,000km on it which isnt bad for them old 5.0l!! Anything i can do to prevent or help it?

 

Yup, your motor is getting tired, not the end of the world. Your PCV system isn't flowing enough to pull out all the blowby, so make it flow more. Check your vent also, not just the PCV.

Don't know the exact details of the PCV system on that motor but if you look I'm sure you can find a way, just need more flow from the valve cover to the manifold. I'd suggest ditching the the actaul valve and just using a fitting, the valve restricts flow. This could effect your idle with more air flow, if so consider blocking the vent that pulls air into the engine.

 

Don't block the vent, it too releases pressure when no manifold vacuum is available(pulling a heavy load, hard acceleration). If anything you could add a breather to the drivers valve cover. Any way for air to escape. It would have to be a baffled breather tho, or oil will leak out it.

 

Check to make sure that the vacuum line on the pcv valve is in good shape. Mine was split and because it's tucked behind the plenum I never saw it.