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Mold in a Corolla

My daughters 2004 Corolla had a clogged ventilation system that was recently cleaned out by the dealer. As my daughter is not one to pay too much attention to her car, the clog may have been there for years. Anyhow, the floor and carpet on the driver side were soaking wet and I suggested, based on something I heard on CarTalk, that she run her air conditioning unit to dry it out. Since she has been doing this, however, she has gotten a couple of asthma attacks and I am thinking that perhaps there is mold in the air ducts that pump the air through the car. Has anyone had this problem? Could it be mold in the vents? And if so, what would you recommend that I do.

Yea. You may well be right.

First I would make sure the drain from the A/C is not clogged. I don’t know about your car, but most cars have a drain that comes out under the car around where the passenger puts their feet. You should see drops of water coming out there on a humid day when the A/C us running.

Second, you can use Lysol or buy a product from the auto parts store. To use it follow the instructions on the can or for Lysol, turn the vent fan on high, make sure it is on fresh are (not re-circulate) and then spray in the vents in front of the windscreen on the passenger side.

OK and thanks. Will the Lysol work its way through the system and come into the car as well? And will Lysol kill mold? How about something like Tilex which does really kill mold? Any thoughts?

Is the mold smell coming from the cabin or the HVAC ducts. You need to determine this first or you can go nowhere. If it is coming from the cabin, you need to replace the carpet and the mat underneath it. If it comes from the HVAC system, you have a much more expensive problem.

If the HVAC system is heavily contaminated, your daughter has asthma attacks from her car, and has learned her lesson, it is might be best to sell the car to someone that does not have allergy problems and buy another. To really clean it out would require pulling out the dash and getting into the ducting and plenum. You could get an estimate for the work and decide. I would guess a kilobuck or so.

I agree with the others. I just want to underline the idea that the mold could easily be coming from the carpeting and padding underneath. Go under the dash where it was wet and pull the carpeting away from the floor up in front of the pedals. I’ll be it’s still wet under the surface. That all has to come out and be replaced, or at least dried out in the full sun for days and days.

Using a chlorine based product in your ductwork will destroy the evaporator of the AC if it gets on it. The mold is more likely in the carpet and the best product for this would be Borax. Make sure the carpets get good and dry and then spread some Borax powder on them. If she has floor mats, they should come out for awhile.