2001 Navigator with mystery oil leak
I have a 2001 Navigator with the 5.4L 32 valve engine. After discovering that my PCV valve was bad, and replaced it along with the rubber elbows that are on the vacuum supply line to the PCV valve, I've now got a substantial oil leak coming from somewhere up on the passenger side of the engine. It is leaking approx 1 qt per 50 miles, so not a good thing!! I managed to strip away the ECU plugs and hoses that covered the passenger side valve cover, since a bad gasket was my first guess. When I wiped all around the cover, I didn't find any traces of oily mess??? So I put the engine back together enough to be able to fire the engine and look from underneath and trace the leak back to it's source. No luck there, because it seems that while sitting still the engine doesn't leak? But when driving it spews oil all over the underside of the truck?? So now I'm at a loss as to where the leak is coming from? I have been able to feel along the rear valley of the intake and found no oily mess. I also checked the oil cooler lines, but they are on the drivers side, along with the oil pressure sending unit.
Any help at this point will be appreciated!! I've not totally ruled out changing the valve cover gasket, but hate to fork out the 60$ if it's not the problem!!