Oil in the air cleaner

[tsmith3720]

What is causing oil to be pushed up into the air cleaner?

[kach22i]

Over filled the oil level?

Should be in the middle of the stick, not top unless planning on aggressive driving according to owners manual.

A small accumulation inside a CIS airbox is fairly normal in my experience.

[stownsen914]

... checked while warm and idling, very important

[kach22i]

My owner manual says at 176F.

Yes, while at idle.


Oil in the air cleaner it's self?

I've never had that happen.

Make sure the new air cleaner is tucked into the top cover, no rubber showing.

[Walt Fricke]

Tsmith - the first commandment of asking for help is to identify your model/year 911. Kach22i has a '77. Those connected the oil tank breather directly to the right side of the air box. Oil from an overfill, or from aerosol oil from the crank case etc will go into the air box under the filter. There is a drain at the front of the box (relative to the car) to let it dribble out on the front of the engine.

At some point (78? 80? 81?) that tube connected instead to the center of the big rubber boot which connects the air meter with the throttle body.

And of course the 3.2s have their system, as do the 2.4s and earlier cars.

So it is pretty helpful if you identify your car.

However, the generic cause is overfilling the oil. And the generic cause of that is looking at the dip stick on a cold ending, seeing it low, and adding oil. You check oil while the engine is hot because as it sits oil migrates from the tank into the engine sump. I was taught to do this at idle, in fact, though some think right after turning it off is best and I am sure that is OK also. It takes a while for the oil to migrate. Only after such a check should you add oil.

If ever you do your own oil change, you will believe all this - you need a big pan under both the oil tank drain, and under the engine oil drain plug if you have let the car cool (not a bad idea) before draining oil.

[GH85Carrera]

After 25 years of checking the oil level in my 1985 I can say this.

Best method, engine up to at least 180 and the thermostat in the fender open and oil flowing to the cooler at a minimum. Let it idle for 60 seconds, then check. Keep it between the two marks, and never at the top mark. If you go out and flog it in hot weather and get the oil to 210 or 220 you will see the oil level higher. Oil does expand with heat.

If the oil temp is not up to the point where the thermostat is sending oil to the front cooler, don't even bother checking the oil, you are wasting time. In the cold winter moths my oil temp never gets hot enough to send oil to the front, and I just ignore oil level. I have driven for hours in 40 degree weather and not gotten the oil hot enough to open the thermostat.

[cmcfaul]

worn rings will cause the case to pressurize and oil vapor to come out the oil breather and air filter.

Chris

[Quickstep192]

I usually check the oil lever after returning from a ride. That way, I know the oil is good and hot and the car is on a level surface. My gauge is reasonably accurate, so I usually sit with the car at idle and wait for the gauge to settle out, then check with the dipstick.