I had the same thing. My PCV actually had yellowish orange coming out of the pcv oil by the throttle
body. There are 6 screws holding your intake to your lower manifold. look at my profile and i have pics. i own a 1999 windstar 3.8 with 167k. and i did this job myself. The screws have seals, and the seals break apart. Letting oil sit inside that plastic intake that your throttle body screws into. Just take it off and clean out both intakes. Replace screws and you wont have that. The screws are 60 from auto zone. But i went to pull a part and got a set that looked decent for less than 10$. Word of warning. If you attempt this. loosen the bolts holding the top piece of plastic to the lower in the specific order stated. I didn't. but i slowly loosened every bolt alternately. The plastic will crack. 150$ right there. The crowl has to come off also. It wasn't that bad. About a days work. But i had to do this to fix my bank one leak engine code. so if you pull it off. get the set of new seals from auto zone that join the intake to the lower manifold.