Whenever I start my LG washer, it smells like sewage in my Laundry Room and then the smell goes away? I have tried running my laundry room sink to see if it's a plumbing issue but that doesn't work.

Please call an expert pretty hard to smell from here.

sounds like a bad computer board

Does it drain into a trap? It sounds like you may not have a trap fitted and the smell from the drains is coming through the outlet pipe?s

i had what sounds like a similar problem. i complained of our laundry smelling sour then finally like sour sewage and a flooded laundry room. i was told that when its not draining properly, it can create a siphon-effect and actually pull the dirty water back out of the drain lines-yuk! i hope this isnt true.
there was a baby sock stuck in the pump preventing it from draining properly. hope your problem can be remedied as easily.
as for the smelly clothes, i always add 1/2 cup white vinegar to each load. it does wonders for odors.

The fan that blows the air blows through the heater coils before it blows through the A/C.As long as the heater doesn't come on, there is not much that can be done. ZCooking the attic room will be a problem because it is the heat rises thing, and on top(literally) of it all, the roof is radiating heat.

Does the sewer drain line have a trap at the bottom that prevents sewer gas from entering the room? If the smell seems to be coming from the washer itself, run a wash cycle empty with a cup of baking soda, detergent and hot water to clean the interior.

some where under your slab your sewer pipe has broken. most times you must cut away the concrete floor and explore for damaged pipes.

Obviously this problem exists on this manufactured machine (Cabrio). It has to do with the design of the machine and the HE detergent required to be used. We are on city water and the smell is sewage gas. Hence, do your whites last with lots of Clorox/bleach, cause the detergent isn't strong enoug to kill the bacteria growing in the pipes. That being said, P

most likely you do have drainage problems where it is backing up

you need to clean out you venting ...it is most likely clogged or filling up