Originally Posted by ghunt
No...it's definitely "sweating" through the hose somehow. There's no other way it would end up on the entire length of the hose, and it's definitely oil.
Heater hose isn't made for the hydrocarbons in fuel and oil so yes, it is sweating through the hose. It will eventually harden it as the rubber in the hose is destroyed, then it will crumble.
PCV hose or emissions hose will work for what you need. Those are typically sold in prepackaged lengths and not by the foot. It doesn't need to be hard plastic line.