[omy12328]

My stang has like two cylinders that misfire and engine light doesn't come on. I checked my spark plugs and found like oil gunk on them. So I cleaned the spark plugs but after I run the car 30 miles the spark plugs get oil gunk on them again. Does anyone know what's wrong with my car. 90,000 miles on it. 1999 mustang 3.8

[Dana W]

Bad head gasket.
Bad piston rings.
bad valve guides.

Any one of those can let oil (and/or coolant in the case of the head gasket) get into the combustion chambers. Once the plug is wet and oily it quits firing.

[omy12328]

I added a filter to the pcv valve line and now oil doesn't suck it's way up to the upper intake. Car runs good now.

[shinerstang]

You have only masked the problem. It is still either rings or valves. Blowby is usually caused by bad rings. But at least your car is not fouling plugs......

[sfracer]

i had the same problem

* replace valve seals
* replace intake valves and manifold valves
* replace head gasket and manifold gasket !!