Paul1307

I have a GS400 and a "new" '05 RX I bought recently. I noticed that the A/C condensate that dripped on the garage floor wasn't as clean as that dripping from my GS; I filed it away under "I may want to look into that some day," and "forgot" about it. When my wife developed a cold, in August, in Florida, I wondered if maybe I had mold in the A/C system. After having read about a dozen threads up here on the subject I headed out to find "something" to flush it out. Here's my adventure!

I got lucky. AutoZone had a standard aerosol container with A/C deodorizer/mold-killer, but the can was so light I thought I'd keep looking. So down to Napa Auto Parts where, lo and behold, they had a "kit" in a small brown cardboard box with the label "A/C Pro Auto Air Conditioning Evaporator Odor Eliminator," and inside the box was an aerosol can - nice and heavy, btw - a cap for the can top, and attached to the top, two feet or so of clear plastic tubing. Ah, so much better!

Folks have recommended that you "spray stuff into the intakes," so I looked for that/them/those first. On each side of the firewall in the engine compartment there are two removable plastic parts that allow access to the area they keep leaves and big stuff out of. I couldn't really see where the intake for the A/C was though, so I consulted my DVD Service Manual ($10 on e-Bay) for where it had to be. While no picture existed of the firewall, it was clear that the heat exchanger for the A/C is directly behind the center console where the radio and heat/A/C controls are. The alternative, it was clear from looking around the engine compartment, was to remove the windshield wipers, arms, and a whole bunch of plastic stuff. Armed with that knowledge I went back out to the car.

Fishing my arm into the hole in the plastic cowling left when the removable "part" was removed on the passenger side, I managed to get my hand in far enough to find a hole in the firewall about dead-center in the car where air seemed to rushing in to the (running-on-high) A/C intake. "That must be the spot," I thought, so I put the cap on the Odor Eliminator can, and did a quick spray to see exactly what "Odor Eliminator" is. Foam! Just like what the forum guys had said the dealers used to clean up A/C systems commercially.

So, back into the hole on the side of the firewall and under the plastic grate goes my arm dragging the plastic hose (It helps if you don't have Popeye forearms). When I'd checked the first time, it was obvious that inside that 3" x 4" or so hole in the firewall, the air went both left and right. And, since I had checked earlier to make sure the fan was downstream of the A/C heat exchanger I was pretty sure I wouldn't lose a finger in the process of killing mold and other nasties. So, pushing the hose to the right, I let loose a stream of foam, and within about eight seconds or so, I'd plugged the whole side with foam. This had to be a success! So, I turned the hose the other way and sprayed the rest of the foam into the left side of the hole until the can was gone. All this while the fan was on high and the A/C was NOT on recirculate, of course.

Did it make a difference? Well I'm sure it must have done some good. The idea of the foam, near as I can tell is that the foam will begin to block some of the passages through the heat exchanger (which is just like a miniature radiator in construction - more or less) and then more foam gets sucked into those areas that aren't yet blocked until the whole thing has foam in it, and whatever the goop is kills the mold, assuming there is any. By "blocking" the right side with foam, then spraying the left side I suspect I got as much foam to as much of the heat exchanger as it was possible to do.

Later, I crawled under the car to see what the drip hose looked like and found that it drips down on a plastic under-body panel, probably covered in road dust and the like, and that probably explained the dirty condensate. But, the "Odor Eliminator" only cost $10, so I figured it was probably a cheap preventive maintenance chore if nothing else.

Later still, I actually read the directions printed in large clear text on the cardboard box it all came in and found that I was supposed to have squirted the foam up through the drip hose. Ah well, stuff happens. All things considered, I think I did the right thing and that, according to the Service Manual pictures, I got to the heat exchanger just fine, sprayed the foam on its intake side which had to help disburse the foam across the whole unit, and killed as much mold as would have been humanly possible, while doing it my way.

Course, others may just follow the directions and miss out on all the fun I had snaking my arm under that plastic cowling, but the that would be their loss, not mine, right? Well anyway, the whole job, including looking at pictures in the service manual didn't take too long, and I didn't have to crawl under the "truck" to get to the leak line, er, drip hose.

A couple of other points. Just spraying Lysol into the open cowl under the hood is a pretty "hit-or-miss" way of trying to get it into the A/C system if you don't know where the intake is located, so if I was going to do something like that, I'd probably get one of those little tubes that come with tuner cleaner and the like to put into the Lysol nozzle before I began spraying it around. And, come to think of it, I'm not even sure that Lysol will kill mold or mildew since most bathroom cleaners don't unless you get something with chlorine or bleach in it, so I'd read the label on the Lysol, or, better still, test it on some convenient mold in the bathroom (if you can find any) just to see whether or not you're actually killing mold or just freshening the air with it.

Same goes for Fabreeze, which I know doesn't kill mold. Anything like that will only have, at best, a temporary effect (although it will satisfy the missus that you at least "did something" even if it was ineffectual). But if you really want to kill the mold you might want to look into the local NAPA store and see if they've got any of that "Evaporator Odor Eliminator." I don't know whether I had mold or not, but I know I feel better, and next time my wife catches a cold I can at least say that I'm pretty sure she didn't get it from breathing in mold from the "new" truck, er, car, or whatever it's called. Total time: maybe 30 minutes; cost: 'bout $10; satisfaction: priceless.