yes, i have a 2001 lightning that does the same. i dont have all the answers on it but apparently its a design flaw with the p.c.v.system causing this under boost conditions. i saw a kit that allegedly rectifies this on e-bay under parts and explains the situation somewhat!!! im reluctant to pop for it though and sort of looked at it as a sales pitch without any real proof it works behind it. good luck.
I just had a frind of mine (hes a mechanic ) take my intercooler out and clean it. What a oil coated nightmare oil coated everything he even said he couldnt beleive what a bad design by ford. I also installed a oil seperator from razors edge and after only 30 miles I had about a teaspoon of oil in the bottom. For $50.00 I think its a good investment.
just so you guys know , if oil gets on your mass air meters if you are having this problem , it will cause your trucks to run LEAN which is bad , make sure to clean it out with brake cleaner and fix the pcv issue , or install breathers in the valve covers , www.modularfordpowerhose.com , this guy has had experience with this problem and has access to some nice breathers for the valve covers .
From what I know the problem is caused by going into boost then releasing the throttle quickly, causing the intake to suck oil thru the pcv system. You can purchase a oil seperator system from several sources. Go to NHTOC.com and do a search for this same topic, you will a truck load of info!
Oh...and I dont believe its as easy as adding valve cover breathers...unless you have your pcm reprogrammed Im pretty sure it will set a code.
I wrote an email to Lightning Enterprise regarding breathers and this is the reply I got:
Personally I have tried it both ways...only no one seems to ever know what
figures to use when allowing for the corrected air entering the open
breather and into the air / fuel ratio.
I have dyno tested with the breather and found that without correcting for
the supposed added air that enters the equation that there is a small amount
of leaning out through mid range RPM but that it equalizes by 4500 - 5000
and doesn't seem to cause detionation during the lean period what so ever...
No I would not reprogram my PCM...besides what figures would you use anyway
as I have no knowledge of any being comprised...