Have you run any air purifiers? I have a nose like a dog, unfortunately, and am super sensitive to a lot of odors. I have an Air IQ hospital grade purifier with multiple charcoal and other kinds of filters. I can often really help with eliminating odors. Rather expensive though.

My handyman had a moisture detector gadget that he recommended I purchase, at Home Depot. He said it wasn't much $$. Perhaps you have a ceiling leak that you don't know about.

I see you said "no issue with ....water leaks" but how do you know that? Perhaps there's a pipe in the ceiling that has sprung a pinhole leak....

But I think maybe it's just old carpet smell, that is more prominent when wet. Might be some kind of mold in the fibers? I don't have expertise in this, but those are the things I'd be thinking about. New carpet for one room isn't going to break the bank, right?

Is there furniture in the room? An adjoining bathroom? Forced air heat/air conditioning?

@kendrah No, ideally I would in the future, but I don't believe a purifier would remove the source of the smell?

@Mrs. S While I have not gone up into the attic space to confirm, I would imagine that if water was, in fact, leaking up there that I would see signs...flaking / bubbling paint, water stains, etc. Also, since the smell was not present until I shampooed the carpet, I don't think it would be a leak up there. The carpet does not smell like the room when I put my nose down to it, even when I pulled it back and gave the backing a smell. The fiber side and the backing both smell 'clean', and the carpet pad smells like carpet pad. The room, thought, smells like dirt.

@Olychick - no, there was nothing in the room when I started to clean, and nothing has been put in there since. The closet in that bedroom shares a wall with a bathroom. I did not shampoo the carpet in the closet, and there is no smell in the bathroom whatsoever. Yes, forced air does circulate in that room.

Thanks to everyone for the replies. When I got home from work today, I pulled the entire carpet out of the bedroom, closed the window, turned the ceiling fan off, and shut the door. Just went in a few minutes ago and the smell is appreciably better. Now the room just kinda smells like the padding and a little bit "fumy" from the glue. I'm going to wait until the morning to confirm, but for now, it seems like the carpet is, in fact, the problem.

Shaun

It is 100% the carpet.

So now Im thinking of making a cleaner (maybe 3% hydrogen peroxide + baking soda), soaking the carpet in the mixture for 30 minutes, then using a pressure washer to rinse it completely. i just need to let it air dry for a few hours. hopefully that does the trick. would that all be a good idea?

A bit irritating that the chem dry cleaning did not remove the odor from the carpet though.

There might have been a chemical reaction with the cleaning product to cause it to gas off. Check to see if, the cleaners has any limitations to specific types of carpets.

Thats not a huge piece of carpet. Could get a remnant, for not a lot of money. I would replace the carpet, so I could be done with it.