gurgling sink question

[roobinsteen]

Hi, glad to be a part of this forum-this is my first post. The main sewer pipe for my house is hung about 5 feet above the basement floor. There is a sink in the basement that is used often. This basement sink has a small sump pump underneath it, which pumps the water up into the ceiling, where it connects to another pipe, and can drain by gravity into the main. Whenever the basement sink pump runs, it causes the sink in the kitchen upstairs to gurgle, sucking the water out of the trap, and releasing bad smells into the kitchen. I do not think that the upstairs pipe that the basement sink pipe connects to has anything else draining into it; only the kitchen sink. How can I remedy this problem? I imagine this is a venting problem. Is there a vent or valve that I should have, but don't? The basement sink pump has what I think is an air admittance valve on top of it. I've attached a few pictures to help make it more clear. I attached 2 pictures of the connection between the pipe coming from the basement sink and the upstairs pipe, 1 picture of where that connects into the main sewer pipe, and 1 more of the valve on top of the pump.

 

[Smooky]

Which one of these pictures is the drain under the kitchen sink that is gurgling?

 

[Sponsor]

 

[roobinsteen]

None! sorry. I didn't include any, for no good reason. Here's 2 pics from under the kitchen sink. I'm not really sure what the purpose of that "loop" is; excuse my ignorance, I'm a plumbing rookie. Also, I was thinking that there needs to be a vent in between, or "upstream" of where my basement sink pipe ties in to the kitchen pipe (which is vented, but after the tie in), because otherwise the vent is useless in this situation. Does there need to be some sort of air admittance valve under the kitchen sink, so that suction from the pump will not cause any suction in the kitchen trap?

 

[Smooky]

You may have other venting issues but I would start with fixing the drain at the kitchen sink.

Take a look at this topic. Terry’s pictures show how your kitchen sink should look if you use an air Admittance Valve (AAV). My post has a link that shows how to fix a similar problem.
https://terrylove.com/forums/index.php?threads/funky-ish-odor-in-kitchen-sink.57841/#post-426561