Because either the trap has evaporated thus allowing sewer gases to enter Or because of soap scum build up from the laundry room and grease deposits from the kitchen sink waste this allows odor causing bacteria to thrive.. The drain lines should be water jetted clean (scoured)
Most likely a drain has dried out and there is no water in the trap to stop the gas from coming up. Sink, shower, or main floor drain.
Could be caused by a couple of things. If you have an onsite septic system (tank and drain field) the tank may be full, and the rainwater is causing it's contents to backup the main drain back in to the house. A vent pipe could be plugged, which causes the sewer gas to back up. If you are hooked to a public sewer, there may be a blockage in the main drain out to the line in the street. Have a plumbing contractor check it out. It can be very dangerous.
A fuel smell inside a house should be ventilated immediately. Open doors and windows and allow this to air out. Scrub the area with a mild soap and hot water to diminish the fuel left on the floor.
What makes a bathroom drain smell, soap makes a bathroom drain smell
Your basement smells like moth balls because you either have the camphor smell throughout your basement or your wall contains the chemical agents in moth balls
Is there a floor drain or any other drain nearby that is not used often? Sometimes the p-trap in a drain will dry out and allow sewer gas to escape. The smell becomes more intense when hot water goes down the drain.
If there's a basement floor drain close by, sometimes the all the water can evaporate out of the trap. This can allow sewer smells into the house. Just run some water thruough the floor drain to fill the trap back up. Ditto for any drain that doesn't get used very often. More input from FAQ Farmers: * Maybe the vent in the wall isn't connected properly or came apart. I would think you'd have a sewer smell all the time but maybe it just gets bad enough when things get stirred up to notice. * Vent pipes are a major source of sewer odors. Vent pipe filters eliminate these odors while removing greenhouse gases. Used zeocarbon is then put back into the soil.
Laundry Detergent
One of the biggest culprits I have found for sewer gas smell is the floor drain many floor drains are seldom if ever used and if unused long enough the water in the trap will evaporate allowing sewer gas to enter the dwelling. this also applies to any trap which is not used regularly.
Try pouring vinegar and baking soda down the drain, or maybe borax laundry powder. Let it sit for a while before running water. If that doesn't work I'd call a plumber. Maybe you need new pipes?
check the drain line on the a/c or does it have antifreeze smell to it then it could be the heater core
The trap in the drain line under the sink is dry. It should have water in it to stop the smell