Musty Odor in Evaporator? Take These Odor Removal Tips
Model: All Models with A/C
Condensation, dust and pollen inside the evaporator case can cause mold to grow and leave a musty odor when the A/C is turned on. This musty odor can occur in all vehicles, not just Hondas, and it’s worse where there’s high humidity.
Although there are treatments available to cut down on that musty odor (usually by spraying odor removal products into the air inlet), these often don’t erase the musty odor for long. Furthermore, some odor removal treatments may even attack the anti-microbial coating on the evaporator core. This can make the musty odor even worse, cause refrigerant leaks, and reduce the life of the core. The best way to cut the musty odor in the evaporator is to remove the evaporator core and clean it. Sure, it’s time consuming, but it really works.
Note: Late models come with a dust and pollen filter. A dirty filter can also leave a musty odor. If the vehicle you’re working on has a filter, remove it before proceeding and see if that musty odor goes away. If it does, replace the filter. If it doesn’t, go ahead with the following procedure.
1. Recover the refrigerant and remove the evaporator case according to the electronic service manual.
2. Separate the case, carefully remove the evaporator core and remove the foam insulation (if it’s not attached to the case).
3. Wash the case halves, the foam insulation and the evaporator core with mild dish soap and hot water. Don’t use bleach or any other type of cleaner/disinfectant/odor removal product; they’ll attack the anti-microbial coating on the core. If the foam insulation is moldy or has a musty odor, replace it.
4. Let the parts thoroughly dry before reassembling them. Remove any debris from the evaporator core fins, the blower, the fresh air intake and the cowl.
5. Reinstall the evaporator core, making sure its drain hose is clear and not kinked.
6. Advise your customers to avoid using perfumes or interior odor removal products, or smoking in the vehicle. These things just make the musty odor worse.
7. Have them keep the evaporator case dry by leaving the blower on (at least on low), even if they’re not running the A/C. Tell them to use the various ventilation modes to direct air where it’s wanted, and, if needed, to use the temperature control to warm the air to a comfortable level.
8. In dry weather, have your customers keep the ventilation system in fresh air mode as much as possible. In humid weather, tell them to keep it in recirculation mode.
9. When they reach the last few blocks before their destination, have them turn off the A/C, but leave the blower on. This stops the A/C’s condensing action that can cause a musty odor, and helps dry the inside of the evaporator case.
Courtesy of ALLDATA
