Mazda6 Weird AC Smell...Help!

[Ty07allstar]

I have an interesting issue. Any time after it rains or my car gets wet, there is a musty smell inside. It smells even worse when using recirc with the AC. Eventually it will go away, I’m assuming this is because whatever is wet dries up. I’ve sprayed stuff into the vents and whatnot to try and eliminate the odor but it keeps coming back. I’m thinking there is water getting in somewhere and when I use recirc, it just blows the smell through the car. Does anyone know where the intake for the hvac is inside the car? I’ve touched around and have not been able to find any place that is wet. Hopefully somebody can help. Thanks!

 

[Lazy2.5]

change the cabin air filter.

 

[Ty07allstar]

change the cabin air filter.

I should have mentioned that I have already changed the cabin filter and checked the drain line and it is draining properly.

 

[Lazy2.5]

I should have mentioned that I have already changed the cabin filter and checked the drain line and it is draining properly.

Take a look on YouTube at some AC/HVAC disinfection/cleaning protocols.

 

[Ty07allstar]

Take a look on YouTube at some AC/HVAC disinfection/cleaning protocols.

That is my next step. I think I'm gonna use a can of Kool-it in the drain pipe at the condensor. I've tried everything and I think it is just gunk build up in the condensor pan.

 

[hsdejong]

This is not an answer to your question, but advice in general.
After using the air conditioning, turn it off for the last five to ten minutes of your trip to dry the evaporator. This prevents mold and bacteria growth in the system, which not only causes smell but is also unhealthy.

 

[Ty07allstar]

This is not an answer to your question, but advice in general.
After using the air conditioning, turn it off for the last five to ten minutes of your trip to dry the evaporator. This prevents mold and bacteria growth in the system, which not only causes smell but is also unhealthy.

I’ve seen that too and will start to do that, and see if it possible helps my problem.

 

[Ty07allstar]

So I ran the Kool-it up through the drain tube into the condensor the other day and ran the AC yesterday and everything seems good. The Kool-it suprisignly didn't smell terrible and just left a "clean" smell in the car. Last night it rained and when I got in this morning the car did not have the musty smell, so I am hoping this was the problem. I have also started turning off the AC before I get home to help dry off the condesor so the water is just not sitting and getting gross.

 

[Ty07allstar]

Well, I washed the car today and afterwards when I got in, it wreaked of musty water. But after opening the doors the smell disapated fairly quick and when I turned on the AC, there was not the usual overwhelming smell from the vents. Not really sure what is going on. I took out the cabin filter and it was bone dry and did not smell at all. I may take off the cowl and take a look to see if something weird is going on against the firewall.

 

[hsdejong]

Is your floor carpet dry?

 

[Ty07allstar]

Is your floor carpet dry?

Nope. I’ve searched everywhere and pulled up the carpet and there is no sign of any water.

 

[tomsdk]

I’ve seen that too and will start to do that, and see if it possible helps my problem.

To be clear, this will prevent the issue from happening. It will NOT fix your current issue. In fact, I recommend against it until smell is removed, because you are bormbarded with bacteria and spores from fungus when the evaporator dries. As long as it's wet, there is less escape from it.
So - when using AC, use it a lot (dont use "eco" mode, and set the fan fairly high). Using AC keeps it clean (flushed by the condensation). But make sure to let it dry if car is sitting for a long time.
And find some foam to spray on the evap itself (I take out the cabin air filter, and spray onto fan, and it takes it to the evap).
And, then clean regularly 1-2 times per year.