[fyrffytr1]

Here's the deal. I have a double sink in the kitchen with a dishwasher drain attached. I started noticing an odor in the recently installed dishwasher when ever the door was opened. Actually my wife told me it was smelling so I checked it out. The drain for the dishwasher was looped above the very bottom of the sink but I noticed (again, my wife told me) that the water would back up in the left side of the sink whenever she drained the water from the right side. I re-positioned the dishwasher drain so the loop is about 3 inches above the sink bottom.
I took the whole sink drain out and replaced it with new stuff. While it was out I used a cheap plumber's snake to work the drain through the wall and as far as I could get it to go.
I can run water all day long through the drain and it doesn't appear to back up but if I fill one side of the sink with over 3 inches of water it will start to drain then bubble up and the water will start to come up in the other side of the sink. It does drain within a minute but my wife thinks there is something still messed up and I kind of agree.
This is the only drain in the house that is acting like this.
Any body got any ideas that might help?

[Brewster]

Check the venting on the sink side to allow flow.

[fyrffytr1]

Originally Posted by Brewster

Check the venting on the sink side to allow flow.

The closest vent is about ten feet upstream from the sink. I think. The drain goes through the wall under a window. The washing machine and laundry room sink are about ten feet beyond that.

[Jeff Hamlin]

Fill both sides/sinks and release the drains simultaneously observe how swiftly it all drains.
If it burps its a good indicator of possible restriction down the line,
which could be either line or vent.
Any minor restriction would still allow some flow and appear to function properly but under full flow can create a backup.

Are age & type of pipe within structure known?
Old cast iron and other metal piping are like arteries and suffer build up with age reducing ability of full volume flow.

[Redpiston]

The drain hose should run along the bottom of the counter top or just below and then attach to dishwasher connection tee on the drop from the sink or connected to a disposal if you have one. If your hose is connected to the drain between the trap and the wall, you will get odor in the washer.

Are you using a single trap for both sinks or does each have its own? Both traps should be at the same height or very close to it on a dual trap. On a single trap the drops should not be short. Some people will make the drops short to get more room under the sink in the cabinet.

[wase]

Hello friend, I've had the same trouble with my kitchen sink. Double sink with drain flow difficulty. Tried as you stated to take the drains under the basin apart to check for obstruction. Nothing was visible. Mine is a Sweet house constructed in 1949 with iron plumbing. After a couple of ineffective attempts with a shorter 15' snake I was able to snake the drain with a 25 foot snake. That was enough to open the obstruction to where the drain could keep up with the flow into the sink from the faucet. running wide open.
Since that was done I have been maintaining it and the other sink drains in the house by dumping a half cup of baking soda down the drain followed by a quart of white vinegar. I allow that to run down the drain and work through the pipes for about 15 minutes. I then follow that up with a half gallon of boiling hot water poured in on top of the fizzing baking powder/ vinegar drain cleaner.
Coconut Butter was the new element in my household that I believe precipitated my drain problem. Pours like water when its warm, hardens like bondo when cooled. lol
Get a longer snake, and send it in as far as you can. Follow up and maintain with the above homemade drain cleaner. It worked for me. Good luck with yours

[fyrffytr1]

The house was built in 1998. I used PVC drain throughout. The dishwasher drain is in the line below the sink but it is looped about 6 inches above the sink bottom. There is no garbage disposal.There is a single trap under the left side of drain. I also found a vent about two feet upstream but my problem is getting to it. 9/12 pitch roof with an aluminum sunporch roof blocking direct access. At 67 with a bad back it will be a challenge for me but I'll figure something out.