It's possible that sink has its own line going to the main city line. I have one kitchen sink in a basement that does that. But I think that is pretty unusual. How far away is the nearest other plumbing fixture like a toilet, shower, or tub?
Can you see any drain lines the basement, particularly where the main drain leaves the house?

There's a half bath about 30 feet away and laundry plumbing about as far away.

I have no way to view what's going on under the slab. Unless... I have a Bluetooth GPS receiver that's idle... :)

Sixto

My general rule of thumb is that I don't call a plumber until I'm sure I've run my snake from the fixture down into the main line. If the nearest toilet is 30' away, there's a good chance your 25' snake has not made it to the main line. You can rent snakes at Home Depot. Don't know if they rent a small one more than 25'. It might be worth it depending on your local snaking charges. Around here, a snake out of a branch line by a plumber will run about $150.

What does your snake look like when you pull it back? Is it all black and gooey or pretty clean? Does it have anything stuck on the end?

The first couple of times it came back gooey and had some fibers thicker than hair. After that it was pretty clean. Not much improvement in flow.

I could check the rental yard tomorrow...

Sixto
87 300D

That's an indication you pushed the plug down the line but probably not out into the main line.

A 50 foot 1/2" auger did it. It being punching a hole through the muck. Nothing came back with the auger except a coating of grease. I'll follow up with more chemicals tonight and read up on proper cleaning of the lines.

Thanks for all the help!

Sixto
87 300D

Good work. It's quite possible that it was just plugged with gooey slime. I'd run straight hot water down that line for about 5 minutes once a month or so to flush out the slime.

I would also run some of that bleach/lye mixture through with hot water at the same time. I think Home Depot sells something to keep slow drains open, probably less concentrated than the fast acting stuff (which, by the way, opens a very slow drain in 10 minutes, usually on the first try.) My wife puts a lot of hair down her drain and it clogs periodically... good luck

Currently i also facing this problem with my home kitchen sink.This information will be helpful for me....thanks everyone.