A plumber would have to check the system, or we would need to see a picture, to make sure whether it is vented properly or not. The plumbing in a two, or more, story structure can be vented properly, but appear not to be to the untrained eye.
: : Hi,
: : I moved into an 83 year old house this past February, and the toilets and sinks have been gurgling when one of the others is used. I have tried to snake the vent stack with a hand operated snake (with the coil spring on the end, not a spade bit yet) but had no luck. I did some exploring to determine about where the blockage is in the vent stack, and found that my vent stack is only about 12 feet long, and connects directly to the 3"/4" (not sure which) waste line running from the upstairs toilet all the way down to the main waste line. Is this incorrect? I assumed that each fixture (sinks, toilets, etc) needed to be linked into the stack separately. If the vent system is incorrect, how bad is it?
: : Thanks for your help.
: If the stack vent (the part above the where the fixtures tie in) is clear of obstructions, the problem is most likely a clogged or partially restricted drain line below where the gurgling noises are occuring.
: The line needs to be snaked and cleaned properly by a professional, hand crank snakes are basically useless unless the clog happens to be in a fixture trap which is not the case here.