Coolant in Oil filler tube
 

I just purchased an 84 RX7 with the 12A motor a few weeks ago, it had a leaking oil pan, so I dropped the pan, cleaned it up and put a new oil pan seal on. Last night I went to fill it back up with oil and noticed a green looking goo/liquid on the inside of the oil filler tube and on the threads of the oil filler cap.

Does this mean I am getting coolant in the engine oil? If so how do I make sure?

If so what is the cause of this?

What are the fixes for this?

Hopefully it is not a complete engine rebuild since I just bought it...

I have my first Spec7 race coming up in a few weeks, hopefully this isn't a huge problem!

Thanks in advance for the advice! I have been searching all over the web for a solution and haven't found any real answers yet.

It could be what is called lung butter from not having the motor vented properly. Do you still have your emissions stuff hooked up? An easy fix it to put a 90* fitting in your oil cap.

I am hoping this is what it is, after some more research, and investigation with the car I think this may be the problem. The car is a road racing car, so no emissions equipment.
The engine runs super smooth with no smoke out of the exhaust. Also, no bubbles, or any oil in the radiator. I think it is a combination of this "lung butter" some corrosion, and the blue VR1 racing oil that was used in the car.

Thanks for the reply!