I posted a thread last year regarding the procedure for cleaning out the mold / mildew smell out of my A/C but actually got around to doing it yesterday. In the event that you have that musty smell I would give this a shot (for reference, mine is a 2007 LE 4x4):

1) Open up the glove box and take out the in-cabin micro filters (search if you don't know how as there are many threads on this).

2) Start the engine and turn the A/C to 70 degrees on FRESH AIR mode.

3) Open up all the vents including the ones in the back (I put the back control on "4" so they were all blowing at full strength).

4) Get some Lysol spray that says it kills mold and mildew (make sure you like the smell of the flavor first :D)

5) Get a old towel and wrap it around the fresh air intake on the cowl (located at the base of the passenger side windsheild) to protect paint / windshield from overspray.

6) Spray the Lysol into the cowl.

7) Go to the inside and smell the vents - if you are happy with the outcome you can switch the engine off and re-install your micro filter. Otherwise repeat step 6.

I ended up using about 1/3 of the can for good measure of the "Professional Strength Fresh Linen Scent" which doesn't smell all that great but it what was in the house and the scent dissipated rather quickly over the course of the day.

I would also let it sit for a while to allow the Lysol to kill the mold / mildew on the evaporator coils - which apparently is where the smell comes from.

There are other products out there that are made for this purpose, but for a quick and cheap fix I'm very happy. If you have stinky A/C, spend $3 and give this a shot!

I will post a follow up in a week or two to see if the stink has subsided - it has been VERY humid in NY lately.

Happy Spraying! ;)

Humid down here as well, and (PU) it does stink!

there are products designed to clean out and remove mold from the evaporator box. one is from Wurth. It's a foam that you spray into the box.

Thx for the advice

there are products designed to clean out and remove mold from the evaporator box. one is from Wurth. It's a foam that you spray into the box.

Agreed. However I had very good results with Lysol so if you want to try this in a pinch it is a good option. When I got home from the city yesterday (after my Armada was baking in the heat and humidity) I turned on my A/C and was pleasantly surprised by the lack of stink as I had grown very accustomed to it. The fragrance of the Lysol had dissapaited as well and all that was left was fresh smelling air.

Seems like the Lysol works pretty good!

spta97,
the service rep at nissan said to do the same thing, but to use the recycled air function and spray in the intake vent (by foot area) for 30 seconds. im sure it does the same thing. i have not done this yet, though it does smell. i plan on replacing the in cabin filter first. currently im at 10K miles. so just waiting a little bit.

wonder what the difference is between spraying the 2 areas. fresh air, or recycled.

spta97,
the service rep at nissan said to do the same thing, but to use the recycled air function and spray in the intake vent (by foot area) for 30 seconds. im sure it does the same thing. i have not done this yet, though it does smell. i plan on replacing the in cabin filter first. currently im at 10K miles. so just waiting a little bit.

wonder what the difference is between spraying the 2 areas. fresh air, or recycled.


I would imagine it would have a similar effect as both should be pulling the air across the coils. With my method though you don't have overspray in your interior ;) But with the fresh air method you are following the standard path so I would try that first. This method I got from a BMW tech and it seems to have worked great so far.

I would check your microfilters as mine are a mess at 18k (2.5 years). Anyone know what the cheapest place to buy them is?

Hey guys. I did this procedure again and this time actually replaced my in-cabin filters (with the Fram ones ~ $20 on Amazon) in an effort to increase my airflow...and boy did they need replacing! It worked well for the front vents but I noted that the rear vents were not getting the fresh smell after I sprayed the cowl with lysol.

Does anyone know if there is a separate intake for the rear ac?

Thanks..

the rear AC gets the air from inside the cabin. back in the rear passenger side i think is where the air get sucked in...

spta97- thanks for this great DIY. After returning home from a shortened trip last night, got right to it with some citrus Lysol. It definitely did the job and smells even better in "fresh" air mode.

spta97- thanks for this great DIY. After returning home from a shortened trip last night, got right to it with some citrus Lysol. It definitely did the job and smells even better in "fresh" air mode.

No problem Primo! This time I noticed that the recirculate was not as fresh as the fresh air mode so I am going to try shooting into the vents when on recirculate.

Anyone know if there is an intake in the truck when you have it on recirculate mode?

Another thing I was thinking of is taking out the micro filters and shooting in there.

I gotta question, I've been trying to do this procedure and I was wondering, do I just spray into the area where the micro-cabin filters were at? If not where is the intake at? The dealer told me that its located on the passenger side of my '04 Armada, but I see no intake anywhere. Help a brother out!!!

I gotta question, I've been trying to do this procedure and I was wondering, do I just spray into the area where the micro-cabin filters were at? If not where is the intake at? The dealer told me that its located on the passenger side of my '04 Armada, but I see no intake anywhere. Help a brother out!!!

I am going to try that as well, but first try spraying in the cowl. It is the vent at the base of the passenger side of the windsheild (outside). It is the same piece that your windshield wipers connect to.

I repeated the procedure yesterday afternoon. While driving on the Meadowbrook, I had the A/C in "fresh" air mode, and it took in a funky scent right after passing the Covanta plant.

After removing the filters, I sprayed the Lysol into the cabin filter housing along with the outside vent. I don't see any harm as air just passes through this area and the Lysol would help sterilize it, along with the ducts/vents.

I repeated the procedure yesterday afternoon. While driving on the Meadowbrook, I had the A/C in "fresh" air mode, and it took in a funky scent right after passing the Covanta plant.

After removing the filters, I sprayed the Lysol into the cabin filter housing along with the outside vent. I don't see any harm as air just passes through this area and the Lysol would help sterilize it, along with the ducts/vents.

My recirculate mode isn't so fresh, I'm gonna try spraying in the filter location and directly into the vents as well.

I sprayed in the location of the cabin filters and that seems to have freshened up the recirculate mode. I still cannot get the ceiling vents in the back to freshen up though - I tried the vents on the passenger side of the 3rd row seat and the hatch but no luck. Any ideas how I can get the vents in the back to take some freshner?

im pretty sure the back system just sucks air in from the atmosphere. if you spray back in the corners and under the 3rd row seats that may help. it will take time for the new scent to "settle in" so repeated uses may be necessary rather than just one time.

It wouldn't make sense that the rear air would use a different intake source that isn't filtered.
I know there is a louvered vent under the vehicle on the drivers side between the rear tire and the bumper however I think that is just for air exiting the cabin. I could be wrong though.

i may be mis-speaking hdcd and i will stand corrected. SCR38 would probably know more.. HEY CPAUL would know im sure... :D ill see if i can find him..

but remember, the main HVAC is not filtered on lots of armadas out there....

It wouldn't make sense that the rear air would use a different intake source that isn't filtered.
I know there is a louvered vent under the vehicle on the drivers side between the rear tire and the bumper however I think that is just for air exiting the cabin. I could be wrong though.

That louvered vent on the drivers side is to release cabin pressure so that you can close the doors and you don't suffocate. It is what keeps fresh air flowing through the vehicle. The air to a intake for the rear is about 6" to a foot from the rear about floor level.