Leak & Mildew problem

I have a 2004 Honda Pilot. It has been fairly dry in Florida over the past 6 months and I have not needed to use the AC. However, when I tried to use it about 2 weeks ago, it was not cooling. I tried it several times over the course of a week to be sure that it was really not working. Over this period of time, I noticed that my car began to smell like mildew, first mildly but by the end of the week it was overpowering. Since it has been dry and we have only had a few brief rain showers, I am convinced that it is related to the AC. I discovered that the floor in the front driver’s side area was soaking wet under the floor mat. That was the only area that was wet. I stopped using the AC until I could get it to the dealer. The dealer replaced the entire AC system (I have an extended warranty)and did a basic check for a leak in the car but was unable to find anything. I specifically asked them to check if there was some sort of leak associated with the AC, but they said that there wasn’t any. I now have to take it back this coming week for the “leak specialist” to try to figure it out. But if the AC was causing it and it has been fixed, I suspect that they will find nothing and therefore will not have to get my car cleaned.

So, now I have this mildew problem in my car and I have tried everything to get it out (febreeze, lysol, etc.). The floor has dried out since I left the mat off. Although it has only been 2 weeks, I have asthma and I cannot drive my car anywhere without having an attack (even with all of the windows down.

Help! What can I do? If the mildew problem was caused by a problem with something covered by warranty, should the cleaning of the car also be covered?

The AC system contains refrigerant which vaporizes if it leaks, so the moisture on the floor did not come directly from the AC, even if the system was leaking, which it may have been since it wasn’t cooling. Is the AC cooling now?

If the ventilation system drain tube is clogged, however, condensation from the AC evaporator (the part that cools the incoming air) and/or rain water can leak onto the vehicle floor rather than drain to the outside.

Someone should check the drain tube and make sure it’s clear.

The mildew problem won’t go away until you remove the padding from under the carpet and allow it to dry. The padding absorbs water like a sponge, and will hold it a LONG time since the carpet traps the water in the padding. This is the source of the mildew and associated odor.

The carpet may feel dry even though the padding underneath is wet. Shop vacs, detailing, carpet cleaning, Fabreze, Lysol, etc, will not extract the water from beneath the carpet. The carpet must be lifted and the padding removed in order to dry it.

This is accomplished by removing the plastic trim pieces at the bottom of the door opening and driver’s side kick panel. The edge of the carpet can then be lifted to access the padding underneath. If you put your hand under the carpet you will be amazed at how wet the padding is.

Thanks for the tip. I just pulled up the carpet and sure enough the padding and foam is wet. I am in the process of drying it now. Now I just have to figure out where the water is coming from…or came from. It seems as though the concentration of water is on the left side of the floor near the wheel well. Any ideas?

The AC system is fixed and cooling now.

When the AC is operating condensation should drip from the drain hose onto the ground. You can see this small puddle behind the front passenger side wheel. If there is no condensation coming out of the drain it could be clogged. If so the water will drip into the car.

Other potential leak sources are the windshield seal, the door gasket, and the sunroof drains (if there is a sunroof), which can also become clogged.

Finding water leaks can be difficult and time consuming. Make sure the drains are clean, because they are the most likely source of the water.

Thanks. I checked the drain hose and it is dipping onto the ground. That pretty much leaves it down to the windshield. Pretty sure the door isn’t leaking and I don’t have a sunroof. The thing that is so strange about it is that we haven’t had much rain, so I don’t know how it could produce so much water.

The dealer has a leak specialist that is going to look at it on Tuesday.

I wondered, also, how all this water got into the car when there hasn’t been a lot of rain.

This may be a one-time event. One good downpour is sometimes enough to overwhelm the HVAC drain.

Good luck.

Thanks for your help. Perhaps the drain hose was clogged and they fixed it when they replaced the AC. Who knows? Hopefully, they will find it on Tuesday.