Well I was performing a radiator bleed today when I noticed an oily substance coming out of my filler neck and into the funnel when the car was shut off. The substance was oily in nature however it was not brown. It looked very similar to vegetable oil. It started to funnel out once the car was shut off. The radiator appears to be the original that came with the car. The coolant I drained appeared pure green before hand. Does anyone know what type of liquid it could be? The radiator looks to be for the original 97 cx and the engine is a b16a2. I will be doing a compression test later on.