i have an 87 f150 with the 300 six, fuel injected. last couple of trips its started blowing oil out the crankcase vent. i've installed a new pcv valve, and yet the problem persists. where is it clogged and why is it throwing it back into the filter. motor seems to run fine, but i guess i'd be happy to with a couple extra quarts every couple hundred miles. thanks

 

Is the PCV valve/system working. If you put your thumb over the end, does it pull a vacuum? If not, the hose may have collapsed inside. If it is working, with the engine running, put your hand over the oil fill opening. You should feel a slight suction with your hand. If there isn't any, or if there is pressure, then you are getting excessive blow-by, or there is a significant vacuum leak that the PCV system can't keep up with. Good luck.