'Hi....My 04 Sonata has a mouldy rotty type of smell when I first start it,.....after the AC has been on for a short time, the smell goes away....Is it maybe mildew or something in the air system? What can be done besides just masking it with an air-freshener?'
REPLY: I am in the HVAC Trade, but not automotive .. Im in residential and commercial. However, the problem is prevalent in both sectors. Heres some food for thought on ridding/greatly reducing what we call 'the smelly socks' syndrome associated with A/C's :
- When you are using your cars A/C and getting near to your destination, shut off the A/C but allow the blower to continue to run . This will evaporate the condensate that has condensed on the surface of the evaporator and reduce the smell buildup. Shut off your A/C at least
3 minutes before youre reading to shutoff your engine.
- If you remove your cabin air filter, you will have direct access to the incoming-air side of the evaporator ; it will be a shiny grey metal object approx. 6" square to the left of the air filter slot. You will only have access to the one side, but, that is better than nothing. Spray some non diluted vinegar on the fins / tubes of the evaporator surface in addition to the plastic condensate pan directly under the evaporator... and allow it to sit there for at least 20 minutes before using the A/C again. Vinegar does a good job of eliminating this particular smell and will not harm the Evaporator or affect its operation. There is no need to rinse the vinegar off as the next time you use the A/C, the condensate will wash off any residue. Initially, you will have a strong odor of vinegar, but it will dissipate in no time. You should be able to go a fairly long time after a treatment.
- At hardware stores, they sell a small stick-on fragranced 'thing' (cardboard) in various scents that you can apply to your cabin air filter ; this will dilute the evaporator smell and make the cars interior smell nice also. Its not very big so it wont restrict airflow thru the air filter . It lasts a fairly long time before you can now longer smell it. Again initially, it is a bit strong but does dilute soon.
- There is a product called Febreze available at Grocery Stores which is pretty good ; you can spray that down the supply air outlets of your car with the Blower off and/or , into the return air cavity of the Blower Assembly located behind your glove box while the Blower is running. Spraying it in the general vicinity behind the glove box is all thats required as it will get immediately sucked into the blower then thru the evaporator and ducting system. It comes in various fragrances and lasts awhile.
Dave