Guys, lets not forget about the PCV valve. Blow by can often be caused by a pluged up PCV valve. It may not by the source of your blow by problem, but if compression is normal, it's an often over looked place to start. Also check all of the PCV plumbing. I don't recall if yo mentioned if it's a Zetec you have chances are the PCV valve was never changed because it is in a BI**H of a place to get at(behind the exhaust manifold). I've seen it a few times with cars I bought from the auction. It's a cheap part to replace in anycase.
