Oil in the air filter

Old 04-11-04, 03:27 AM
J Irish
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Oil in the air filter

I have a 1990 Ford f-250 5.8 liter . I'm getting a lot of oil in the air box. What would cause this?
Old 04-11-04, 07:57 PM
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Hello: J Irish

Check the PCV (smog valve) if equipped with one.
PCV stands for Positive Crankcase Ventilation.

If your state is like mine, there will be a PCV valve for the smog system. Located on one of the valve covers. If the valve is plugged, restricted or stuck open, etc, may cause crankcase pressure to build up if defective.

Excessive blowby may also be possible. Blowby is compression which passes by the pistion rings and enters the crankcase. Causing pressures to buildup in the crankcase. Oil mist then blows up into the air filter or air filter area, etc.

The mechanic pros will provide more info. Check back on your question several additional times over next few days.

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Old 04-14-04, 03:31 PM
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Another thing to check is if under the pcv grommet there is a metal filter that gets plugged.Not all Fords had them so I'm not sure if it applies to you.This would be if the pcv valve is in the back of the intake manifold.

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