Sorry to bring this up again. But I am having recurring problem with my AC. I have a 94 E420 and I am a second owner. The car has low miles and the it wasn't really driven that much (ie. the AC hasn't been used that much.) So far, I have done the followings:
1) changed air filter
2) use lysol - like many members suggested.

1) really didn't help. 2) helps temporarily for a whort period of time. But I am looking for a permanent solution. Isn't there a way to somehow clean this out? I thought about replacing the AC gas (is it R12?). Will that help?

I've searched the message board and lysol apprears to be what people suggest but this is not a permanent solution.

Thanks

You must have a leak somewhere!!!! How is the AC/heater working?

Bad smell from A/C
 

two potential causes one cheap to fix, one not

1) cheap mold and mildew in the ducts and drain pan causing foul odor. Solution is to flush with water containing a few tablespoons of bleach (chlorine) in a gallon of warm to hot water. Pour it in the air intake slowly (like over 2-3 minutes) with the fan running. Leave it for a couple of hours, then flush with fresh water just the same. You have to kill the mold and mildew, not just cover it up.

2) If the smell is 'sweet' and stronger when you turn on the defroster, you have a small antifreeze leak. Fix is remove and replace the defective heater core. (15-20 hrs + $200 for new part) unless you are in warranty coverage somehow.

You just asked the question I was thinking. What does it smell like? That'll help to diagnose the source. Hopefully it's just the musty Grandma's attic smell.

update
 

I am not sure exactly what a "sweet" smell is.. but it's more of old attic smell than anything else. I tried doing the bleech thing as stated above. The car smells like bleech now so I can't tell if it's working or not. I will keep you posted. It's very annoying. The smell goes away after 30 seconds or so but I really want to get rid of the initial smell.

Also check the drains under the chassis.
One each side of tranny. They are one way valve/hose and stick closed. Stick a screwdriver up them to clear.