Help: Oil in my 07 STS Air Box

[BobsArmory]

So yesterday I decided to change the air filter on my wifes 2007 Cadillac AWD V-6 STS 160,000 miles. When I pulled out the old Air Filter I thought I saw water in the bottom of the air box so I pulled out the top of the box and the plastic piping that connects the air box to the engine intake to clean it.

What I found wasn't water but engine oil in both the pipe and air box(intake manifold was dry). No problem I say! I just need to get a new PCV valve and that should take care of it.

I go to NAPA and Autozone and they both say they don't list or stock a PCV for this car. OK, I'll just run down the street and stop off at the Chevy/Buick/GMC Dealer and get one. Guess what? No Dice. In the diagram they show the hose coming out of the rear end of the left valve cover to the air intake pipe and a"fitting engine crank case ventilation" Part #12578316 but no PCV valve.

So I have 2 questions:
1. Does this car have a PCV, might it be hidden inside the engine?
2. What could be causing oil to leave the left valve cover and travel to the Air Box?

 

[artificialist]

Sometimes instead of a PCV valve, there is a fixed orifice between the intake manifold and the crankcase. If the part that leads into the intake manifold gets covered in sludge, the crankcase gasses will exit out of the fresh air inlet. Sometimes oil is mixed in, because an oil separator would only be needed between the intake manifold and crankcase. That inlet is very often near the engine air filter, and that may be why you have oil on your air filter.

Replace all the hoses you can replace, blast air intake cleaner down the hard parts, and things should go back to normal.

You might have to change the valve cover where the crankcase vent to intake manifold is located.

 

[hsd]

Not sure about your Caddy, but a number of vehicles like my old 4.0 Jeep do not use PCV valves, just an orifice usually in the valve cover fitting. If the orifice or line to the intake manifold gets restricted the blowby will go out where ever it can, usually the fresh air tube on the air filter housing. Hopefully cleaning out the lines and orifice will fix your problem but if not you may have developed too much blowby for the system to handle.

 

[tightwad]

Yours is just like my DTS. It has a fixed orifice PCV. It is the fitting you referenced in the valve cover. Just needs to be inspected and cleaned if necessary. BTW, mine has a lifetime fuel filter in the tank. Yours might have one also.

 

[BobsArmory]

Just removed and cleaned the vent hose and fitting that exited the valve cover. Couldn't seem to find any orifice but I cleaned it out anyway with some spray carb cleaner. Ran the engine without the hose and didn't feel any air rushing out of the valve cover either. I'll let it go for a week and recheck to see if any more oil comes out.

Let me know if you all have any other ideas.