Originally Posted By: c3po
Originally Posted By: onion
Personally, I wouldn't bother. A thin film like that won't cause you any problems. And it's negligible compared to the crusty critters that are likely built up on the back side of your valves.
Originally Posted By: c3po
What caused that too happen, was it oil mist getting past the PCV Valve or is that a faulty EGR Valve causing that buildup.
This is quite common on even well-maintained engines. The crud likely comes from both sources, and the EGR valve doesn't have to be faulty to cause this.
This happened on a Ford engine, and I have a Mercury Marauder which is a Ford product, how do I prevent this from happening.
The owner's manual says to change the PCV at 100,000 miles. I think I will be changing it at 30,000 miles.
Brent- When they did away with throttle body injection and carbs, the blow-by gas no longer had a solvent fuel wash down throughout the entire intake system. If you've pulled a carb off of an intake, you would (probably) see a bit of a stain where the PCV port hit the intake ..and then a lighter stain trailing off into nothing. This can no longer occur in a "self maintaining" manner. Now the blow-by vapors hit the pulsing environment (much larger) of the intake and the heavier particles sink out. They migrate to the point of injection where they get dissolved ..just like they used to when the air:fuel mixture washed them down before.
The EGR process adds to this too, but not as much as the PCV system.
You cannot avoid this unless you can clean the blow-by evacuation process before it hits the intake. That's why onion says that it's normal.
I would have a hard time leaving it there once I had access to it.
