A/C related smell

You can use the rather toxic A/C cleaners commonly available, find a shop that will use ozone to clean out the system, or make your own cleaner with vodka and cider vinegar, believe it or not. To reduce the smell, always turn the A/C and recirculate controls off well before you shut the engine off, to dry out the coils. Also make sure the condensate drain isn't blocked.

The drain may need to be cleaned out. It is nothing more than a plastic tube that runs from the drain pan to the underside of the car near the passenger's feet. Cleaning is done by running a cleaning rod of some sort up the tube or by blowing air through it. If the drain plugs up altogether it is common for the drain pan to overflow with condensed water and soak the carpet on the passenger side.

This is a very common problem and not often easy to correct. The smell comes from mold trying to grow in the evaporator and drain pan. IIRC it was one of the regulars here that came up with a vodka procedure (no kidding!) to knock down the mold - maybe he will update me. This product has had good reviews, too:

Thanks for the heads-up. I'm glad that this is a common occurrence :-) Where can I find some drawings or procedure description about this thing? Is this tube accessible from the interior?

Thank you.

The interior end is hidden under the dash, but the outside end isn't hard to find on a muggy day. When the A/C runs and there is humidity in the air the drain tube will drip water (unless it is completely plugged). If you let the car idle a few minutes with the windows open and the A/C on you will see a puddle forming on the ground near the passenger door - that is dripping from the drain.

You may want to spend the modest amount to have an A/C pro check it out. They can ensure the drain is clear and probably have a procedure that works well.

Mike

Here it is. I had to do a web search myself to find it. ;-)

Non-toxic A/C System Cleaner

Mold, mildew and fungus growth in automotive A/C systems is a common problem, especially when the air intake control is regularly set to "recirculate" or "Max A/C". There are commercial cleaners available that can control the problem, but I have yet to locate one that isn't both moderately toxic and strong-smelling. Since I'm somewhat sensitive to noxious odors and to chemicals like ammonia, I have developed an easy to mix, non-toxic alternative that, for me at least, works as well as or better than the commercial products. In the interest of a less-toxic environment and as a public service, I am posting it.

Materials Needed:

Clean adjustable spray bottle, preferably 24oz or smaller.

Cheap vodka

Apple cider vinegar

It is probably possible to use white wine vinegar, but I haven't tried it. Feel free to experiment, at your own risk. Mix the two ingredients in the bottle: three or four parts vodka to one part cider vinegar.

Application:

With the recirculate control set to "fresh", the ventilation fan on medium, all windows open ,and the engine and A/C running, spray generous amounts of the mixture into all of the outside air intakes. These intakes are usually located at the base of the windshield. If the system is already seriously moldy, wait a minute, set the air intake control to "recirculate" or "Max A/C", and spray the mixture into the air recirculate intake, usually located above the front passenger footwell, or sometimes behind the glovebox. Let the A/C and fan run for another minute or two, then switch off first the A/C, then the engine. The car will smell strongly of vinegar for an hour or two, but I find this to be both far preferable to the smell of the commercial cleaners and shorter-lived. Leave the windows open a little when finished, if possible. Like commercial cleaners, one application may not be enough, so I suggest weekly applications until the problem is gone, then preventative treatment once a month during warm weather.

Precautions:

This formula is non-toxic, but not completely harmless. Use common sense when applying it. That means not getting the spray in eyes, nose or open wounds, and not applying it with people or animals in the vehicle. Depending on the proportions (and again like some commercial products) the mixture may be flammable, so don't apply it while smoking or near any combustion source.

As with the commercial cleaners, remove any residue from painted and/or plastic surfaces after application, as it may harm the finish.

Finally, don't drive the vehicle until the vapor has dissipated; not only is there a slight potential for intoxication, there is also the possibility that this cleaner can produce a false positive on a police breath alcohol analyzer.

Thanks.

It sounds so fun that I'll try this method tomorrow. As I don't have any wodka at home (and the tzuica I drink is far too precious for this purpose), I think I'll substitute sanitary (ethylic) alcohol for it.

One thing I guess I have to check is if the tube is still draining (i.e. if I get a condensate pool under the car). If not, the car will see the mechanic.

B.t.w., the A/C was seldom used (I'm a MPG fanatic) and always on Fresh intake. It's the age and the fact that the A/C system was never serviced.

Kind regards

I'm also a 'MPG fanatic', but I've found that the A/C uses little fuel if you don't mind turning it off to accelerate and to climb hills. Years ago I even built a unit that used a headlight relay to turn the A/C on only when the brakes were being applied. It was perfect for city driving.

It is a common occurrence and the suggestions offered so far are good, but here is something easy that works for me. Anticipate arrival at your destination and turn the AC off a mile or so before you get there. Run the fan at full blast. The cabin doesn't heat up much and it completely eliminates the problem in both my Hondas. (At least to the extent of my ability to smell it.)

Not familiar with that year but make sure it doesn't have a cabin filter. A

"mjc13 @verizon.net>"

I don't think the Civics have such a thing; there's no mention of a cabin filter in the Owner's Manual.

I have the problem with my Chrysler of the mid 90s. I bought from the dealer a commercial A/C duct cleaner they use. Whenever I get that stale smell, about 3 times per year in our moist climate, I spray it into the outside air intake with fans running and select the various A/C duct options for a few minutes each, just before garaging my car for the evening. The next morning it's fine.