Help with drain noise from downstairs

[chetos]

The drain from the downstairs wash machine connects to the upstairs sink/dishwasher from upstairs before it heads under ground. When the wash machine is in use, the upstairs sink girgles. Nothing ever comes up but you can just hear it. Is it vented correctly? This looks like it was done after the house was built as there is no vent for this before it hits the main.
How could you install a vent without doing major reconstrunction to get it through the roof? THanks.

[Drain Medic]

Well the 1st question is this...How long has it been gurgling? How long have you lived in the house? Main question is how long has it been gurgling...If it is a new gurgle....Then you may have a partial clog in the line past the sweep of the stack...maybe lint buildup and grease buildup. Maybe a partial clog in the stack itself..

[chetos]

Well the 1st question is this...How long has it been gurgling? How long have you lived in the house? Main question is how long has it been gurgling...If it is a new gurgle....Then you may have a partial clog in the line past the sweep of the stack...maybe lint buildup and grease buildup. Maybe a partial clog in the stack itself..

maybe gurgle was the wrong choice of words. It's always done it. We just had that section cleaned of from lint and it still does it. It drains just find. Just noise...

[Drain Medic]

Sounds like a venting problem...maybe a clog on the roof or in one of the offsets before the kitchen sink line

[Ace Sewer]

agree; if line is clean then it is a vent issue. which is the unvented add on? the washer, or the sink upstairs, or all of it? if the sink upstairs is vented to the roof, i agree with dm.. vent clogged. no vent on wash line should make no diff to sink uptairs if it is properly vented. if sink not vented, then put a vent in or resign yourself to listening to it.

-Alex

[gear junkie]

You can install a studor maxi vent at a washing machine but will require some demolition and plumbing know how.

Thinking out loud here guys; if he were to take off his upstairs p-trap and run the washing machine and place a piece of TP on the pipe and it stuck, would this easily prove it's the vent? It's late so ignore if incoherent.