I'll start with the first problem, the kitchen drain/pipe. I live in an apartment building, and when the person directly above me runs water down his sink, I was hearing a loud gurgling noise right below my sink's drain and occasionally some water would back-up into my sink. It would then drain away and I've never noticed the drain acting slow when I've used the sink. But a few years ago I had a more dramatic version of the problem, where I came home to a flooded kitchen because the pipe had blocked, unbeknownst to the tenant above me. At the time they snaked the pipe from my sink, and the problem seemed to go away. But when I started hearing the gurgling noise, I left a message for the maintenance person (it's impossible to get him in person). I explained the situation and the past problem.

Then yesterday I came home to see he'd been working in my apartment, but mainly in the bathroom from what I can tell. So it's possible he misunderstood which sink I was referring to, or the work is related--no clue. Anyhow, he appears to have worked on the drain under the bathroom sink. But now I have a new problem--whenever the person above me flushes the toilet or runs water I notice a sewage/burning hair type odor. Not completely overpowering, but not pleasant either. I do NOT notice it when I flush my toilet or run water. The toilet, mine at least, doesn't bubble when flushed. But I do hear water running in it faintly if I run the bathroom faucet, or if the person upstairs runs water (this has always been the case--it's not a new thing). Could the odor just be a temporary result from snaking the pipe, or is this a venting problem? (I have no way of seeing where/how anything vents, I don't think.) Or something else?

Then this morning I heard the gurgling noise in the kitchen sink again, so I can't tell whether he tried (and failed) to fix it and that it was related to the bathroom work he did, or if he misunderstood what I was describing. Ugh.

So, I intend to call maintenance again, but I haven't had a super response in the past. But I guess my questions are:

• Could the bathroom work have been related to the kitchen sink? The rooms aren't too far away from each other, and this is an old building.
• Is the gurgling sink a partially blocked pipe that needs to be snaked?
• Is the bathroom smell a pipe/venting/other problem? Or could it just be temporary? It's weird I don't smell anything when I run water.
• Both these are fairly important things to fix, right? I hate being a pest, but I don't want another plumbing mess either.

If you've managed to make it through this message, thanks in advance!

Just bumping this to see if anyone has any ideas.