drainage: not the usual suspects.

[TPG]

I Have a sink that's slow to drain. i popped the screen off and snaked the drain, then took off p trap and cleaned it out. most times i have a slow drain this does the trick. but this time i put everything back together and my drain is still running slow, so i thought it might be the larger waste line in the wall, but i have another sink right on the other side of the wall and it drains fine, so im wondering,once i have the p trap off should i, or can i snake the pipe coming out of the wall ? is it safe to do so ? (aside from the usual snaking risks) and will it even help or reach anything useful? i have just a normal hand snake 15 foot although Ive never gotten it more than 2-3 feet in anything
thanks for reading and any helpful comments !

[TPG]

also forgot to mention that when i run the sink and the water starts to fill up once it begins to drain ( after i turn off water) it bubbles quite a bit and gurgles just a tad

[Redwood]

If the 2 sinks do indeed connect to the same point inside the wall the clog would be between where they connect and the sink that doesn't drain...

Where that is and what to do I can't say without being there, but you haven't tickled the spot yet...

[HayZee518]

the gurgling means the drain is starving for air. where the drain connects in the wall downward is towards the main waste line. above the tee is the stack. there could be a partial blockage in the vertical vent line. if your kitchen stack goes through the roof check the line

[Redwood]

Starving for air and venting is a common misperception on a clogged line.

There are limited times the lack of a vent will cause poor drainage, in fact drains without vents do drain very well toilets and s-traps being a prime example.

The gurgling is trapped air coming up through the water filled drain escaping from the line.