Funny smell in bathroom

I’m ready to believe in Satan simply on the strength of whatever is haunting my sink.

Got home and removed the P trap and other stuff below the sink. I’m looking at a bare sink bowl, no faucet, no drain plug, nothing. There’s a short stub of pipe coming out the bottom of the sink under the vanity. I cover the end of that with plastic and tape it shut. Check that smell is still present. Double-check that the various bits of piping and P trap are not the source of said smell. Stick head under vanity, can’t smell it particularly under the sink (so it’s not the cabinet itself, or where the pipes come out of the wall).

Proceed to fill the bowl with a strong bleach & water mixture (I’d guess 1-2 cups bleach to less than a gallon of water. I actually squirted some raw bleach right down the overflow vent with a turkey baster (don’t think I’ll be using it on any turkeys from now on) first, then began pouring the bleach and water mixture down the overflow vent through a funnel (to make sure that it’s really washing stuff out). Continue until the sink bowl is full, right up to the overflow vent. Watch as some chunks of ick slide out of the overflow vents (where it joins the drain). Remove chunks and dispose down toilet.

Amused myself for an hour while sink sat detoxifying.

Drain sink, hook back up to plumbing, rinse clean with several buckets of hot water (first, to get rid of the bleach), then hot soapy water (to remove any remaining bits of crud), including pouring directly down the overflow vent through the funnel again. Don’t see other chunks of stuff coming out, water is flowing very freely.

Still stinks.

Run some more hot soapy water down, this time using a big ole glug of antibacterial soap. Rinse again. Still stinks.

Break out the soap scum dissolver (organic, basically nontoxic), squirt right into overflow holes (where joins the drain, since smell seems to be coming from there, I don’t get much odor when I sniff the overflow vent itself, up at the top of the bowl), let sit, rinse again. Still stinks.

Use a probe to check vent and drain to make sure that nothing appears to be clogged in there.

Notice a bit of scunge still coating the drain pipe itself (the three inches that is actually part of the sink bowl), scour clean with comet and an old toothbrush. Rinse. Still stinks.

Scrub with baking soda, flush with vinegar, let sit, rinse. Still stinks.

As far as I can tell the damn sink is approaching surgically clean limits (aside from that damn odor). I’m not sure what else I can possibly clean, or even use to do the cleaning.

Can anyone think of anything that I might have missed? It’s definitely the sink that is the source of the smell and per my previous post I am now seriously considering just prying the sink out and putting a new bowl in(it’s an inexpensive oval porcelain one, I checked Home Despot and can replace it for about $40). This is like the urban legend about the car with the “smell of death” only I swear on a stack of bibles that I’m not making this up.

I am a little confused when you say you removed the drain plug but there is still a pipe coming out of the bottom. Those two parts normally screw together to form a seal around the overflow outlet and make up the pop up assembly. I have never seen a sink (not that they don’t make them) where the “tail piece” (the pipe coming out of the bottom) is made as part of the sink. I think if you wiggle it around it will pull out, then you can really clean out the overflow outlet. If you notice, you can sometimes see the overflow mould from under the bottom of the sink, the overflow goes completely around the bottom of the sink so it has some capacity to hold funk in it. You will probably need plumbers putty to reassemble all of those parts as they have a tendency to leak.

I am still pretty sure that is where you odor is coming from however some other possibilities could be a cracked or broken sewer or vent line that could be emitting odors whenever you run water. Your facet is already removed but sometimes the cheap plastic ones leak water back inside from the outlet and get rather slimy and smelly at times. I’d also be sure to have taped off the drain line outlet, you could be getting a smell out of there that is coming up through the open faucet holes.
On the other hand forty bucks for a new sink doesn’t sound all that bad either.
Rikster