Oil in Intake Manifold
I've been taking care of maintenance on the girlfriends car, a 2006 Cobalt LE with 2.2 engine, about 110,000 miles. She bought the car used 4 years ago and has been diligent in changing oil. I have been using full synthetic when she asks for oil to changed, when the message center lets her know it's due, for the past 3 years.
She complained the car nearly stalls at stops occasionally. So I removed the throttle body to clean it. It was dirty, clean now, but I noticed a puddle of oil in the bottom of the intake manifold. Also there is some white goo in the air box above the throttle body and in the rubber tube that runs from valve cover to the air box. The coolant level is normal, and she drives long enough usually to fully warm the engine, about 20 minutes to work.
So I am thinking there is there is some blow by or a problem with the PCV system and not sure about the white goo. I've seen to goo on other cars that are used for short distance driving. But not quite as much, there might have been 1 to 2 ounces of the white goo. I used a long screwdriver as a dipstick to measure how much oil is in the intake manifold. Looks like about 3/16".
How does this PCV system work? Haynes manual shows only the tube from the valve cover to the air box and a baffle in the valve cover as being the entire PCV system. Seems like there should be an actual PCV valve or another vent somewhere.
I am thinking of adding a catch can unless there is some other simple problem to repaired. The car does not use oil between oil changes. Perhaps it's wrong to say none, but it is not evident on the dipstick between oil changes, so perhaps a few ounces per oil change adds up in the bottom of the intake manifold over many oil changes.