That sounds like the intercooler hose. It goes onto the pipe going over the top of engine and is about the diameter of a coffee cup. The top radiator hose is the smaller diameter hose in an "L" shape directly below it and goes on the the thermostat housing on the side of the engine (cylinder head).

Your intercooler/tubo/induction (pick your own terminoligy, they all mean the same thing) pipe will always have a thin coating of oil in it due to the fact that the turbo will always pass a very small amount of oil past it's seals. If it starts to pour oil out then it's indicative that the turbo is on it's way out.

If the hose keeps filling up with oil, I would start looking at having your turbo reconned.

P.S. It's always a good idea to check your oil and water levels. You can never check things like this too much. Don't over fill either the header tank with water/anti freeze or the engine with oil.

If you over fill the oil, it will try and force the excess out which means blowing it past seals and such like. If you over fill the header tank, the same will happen. The pressure build up will force out the excess water and you will think that it's over heating when all the water is doing is trying to expand into space that isn't in the tank any more.