I've just been round, and it was another auto car I was thinking of, the mk3 astra I drive.
I can't readily see any pipe.
Do you have any more info, what size is the pipe ?
I don't remember these having a vac connection in that area, if you hear a gurgling it suggests it could be a breather, but can't see why it would gurgle as shouldn't be in the oil, the breather for the gearbox is further towards the front of the gearbox, very visible a metal valve on the front steel casing.
I think it may be the PCV valve pipe, this leads from a fitting on the front of the engine behind the exhaust, which has a PCV valve in it, from this one way valve it goes to a "T" piece by the rear corner of the head on the nearside and into the inlet flange.
The purpose of this Positive Crankcase Ventilation Valve(PCV) is to allow the engine to suck the pressure out from within the engine when cruising etc, at idle the spring inside the pcv valve shuts off so the engine doesn't suck, otherwise it makes the engine run very rough and very lean, as this is extra oxygen not accounted for.
The pcv valve housing is a box type device bolted to the front of the engine, with a rubber bush in it into which the valve sits.
All your syptoms tally, best advice if you don't know your way around an engine is a haynes manual, you'll be shocked at how easy some jobs are, and save yourself loads of cash into the bargain!!
tabetha