My 04 BMW when you turn on the AC emits a really bad smell .... Tried air fresheners and everything in the vent, but it still smells like shit, any help?
If you smell anti-freeze it could be your heater core. If it smells like crap, you probably need to service your coolant system. It gets plugged up and starts to stink. If it is not one of those two things, I'd say an animal may have crawled in your engine compartment and died. Which will be hard to find.
Your problem reminds me of a Seinfeld episode where Jerry's BMW gets stunk up by some smelly guy, and Jerry can not get rid of the smell so he lets someone steal the car. Cheers. Hope you find the stink.
I'd start with the coolant system flush and see if that helps. Also change your in-cabin air filters, if car is equipped with them.