I've had my Boxster 2000 S (43,000 miles) for almost three years. When I first turn the key and the vent fan starts, the air has a musty/mildewy odor. I've replaced the cabin filter twice in three years, sprayed alcohol into the air intake while the filter was out, and sprayed down into the dash vents, but no help. My guess was that mildew was growing on the evaporator and there wasn't much I could do, so I've just ignored it.
Last week I had the complete evaporator box replaced because it had a refrigerant leak -- evaporator, heater core, drier, and the enclosing box. I drove it about 1-1/2 hours back home with the A/C on, let it sit for a few days, and today the same odor persists.
I always keep the rain drains clear and there's no wet carpet in the footwell area. I can't prove that the evaporator drain is open, but I see the usual condensation drip trail when I pull into the garage. I'm not sure where the mildew could be living, if that's what it is.
The odor isn't horrible but I'd like to clear it up. Any ideas for the cause? If there a good product to use to clear the odor?
Thanks in advance!