Detached garage plumbing issue

[46MGTC]

I've got a new issue in the garage. There is a sink and toilet that has been working fine for the past 5 years or so. The rough was done by the plumber that did the house. I did the final install myself about a year later so so it may not be the most pro job but it had been working fine. I used a Studor air valve under the sink as I didn't want punch through the roof.

Anyway, out of the blue, one day last week the toilet started burping and gurgling after flushing. I removed the Studor and the toilet works just great. With the paint fumes, blast cabinet dust, etc. I thought the Studor had become gummed up so I replaced it. The burping came back. Now thinking that I may have a clog in the line to the septic tank I opened the cleanout and dumped about 5 gallons of water which drained easily. With the cleanout open the toilet now work fine again. So I guess I've got some kind of venting issue but where do I go from here? The line from the toilet to the cleanout is, of course, under the poured concrete floor.

Any ideas?

Forgot to add that I've plungered the hell out the toilet with no change in symptoms.

 

[Slowgsr]

Snake it? I hate plumbing

 

[tyjoja]

i'd say partial clog between toilet/sink and clean out

 

[Dick in Wisconsin]

Think back to just before you first noticed the issue. What had you been eating two days before.

 

[46MGTC]

Thanks for the tips. Maybe it was the double bean burritos

Any other suggestions? I guess I get to buy a plumbing snake.

 

[nadogail]

A "water weenie" will most times do the trick, smaller and cheaper than a snake.
They are sold under the Drain King label.

 

[nadogail]

A Drain King unclogger from Lowes or Home Depot is cheaper and easier.

 

[gasgas17]

remove the vent and tread a plug in there. then try plunging the sink. If no luck with that, snake from the sink to the clean out.

 

[theoldwizard1]

remove the vent and tread a plug in there. then try plunging the sink. If no luck with that, snake from the sink to the clean out.

Better yet, tie a 5' piece of heavy chain to a piece of rope about 25' long. Tie the rope off to something secure drop it down the vent. Repeat a couple of time while running the water from a garden hose down the vent.

 

[mike_dmt]

Fill the sink to the top, and then let drain, listen to the Studor(which work fine). If it drains slow or burps, its the Studor. If not, the drainage problem is the toilet.


I'd guess the plumber roughed in with 3" minimum, hopefully 4", which would almost work as a "combo" vent system. The flow from the toilet simply cant fill a 3 or 4 inch line, so the available space in the line works as a vent. If that makes sense.

My thinking is, if you poured gallons down the cleanout with no issues, it's 99.9% probable it's upstream.