Stench/Smell from A/C vents

[AddictedUSAF]

Tried searching this, could not come up with anything. My wife's 4runner has developed a annoying smell from the a/c system the car is only a 1 year old I would not think the cabin air filter would need to be changed yet. So what else do you guys think could be causing the smell? Never had this issue with any of my vehicles. Thanks, Cody:thumb3:

 

[1engineer]

Remove the cabin filter and check it yourself. Chances are it needs a new one.

 

[GrantK]

As 1engineer says, check the cabin filter. You might have some leaves (or worse) in it that are decaying which wouldn't smell like roses.

 

[AddictedUSAF]

Remove the cabin filter and check it yourself. Chances are it needs a new one.

I will for sure when she gets home today. Just never thought it could be that since the climate/conditions we drive in. We don't get much trash/junk/dirt where we drive it. Thanks for the input.

 

[AddictedUSAF]

As 1engineer says, check the cabin filter. You might have some leaves (or worse) in it that are decaying which wouldn't smell like roses.

I agree with you totally. It always a possibility. Thanks

 

[Jtraskell]

If your cabin filter is relatively clean, this may be another reason. Is the smell kinda of like mold? You are in Houston, I live in Florida. I suspect we both use our AC a lot. What I have learned since being down here is that unless you shut off the AC unit say 1/2 mile or so from the house, keeping the fan on and use outside air vs. recirculating the inside cabin air, the moisture (condensation) that builds up on the evaporator allows mold to build up.

If you allow the system to "dry out" after each use, no mold build up. No smell. Be safe.

 

[mrvandelay]

Can you not just blame it on the dog?

 

[AddictedUSAF]

If your cabin filter is relatively clean, this may be another reason. Is the smell kinda of like mold? You are in Houston, I live in Florida. I suspect we both use our AC a lot. What I have learned since being down here is that unless you shut off the AC unit say 1/2 mile or so from the house, keeping the fan on and use outside air vs. recirculating the inside cabin air, the moisture (condensation) that builds up on the evaporator allows mold to build up.

If you allow the system to "dry out" after each use, no mold build up. No smell. Be safe.

I have heard of doing this in the past, but....my wife drives it on a daily basis and I doubt she will remember to do this. I know that works though. She said today it kinda smelt like pee. lol

 

[Jtraskell]

Yea, that's mold. Not sure which one, don't wanna either...lol. I am going to look, but maybe the collective can inform OP where and how to get to the evaporator just in case it is not the cabin filter. If it is easy to get too, some Lysol or bleach should do the trick until next time.....Be Safe.

 

[AddictedUSAF]

Fack!!!!!! That sucks, bc usually that involves removing the blower unit ect....

 

[Jtraskell]

Well, hold on now. It may be something simple like something in the cabin filter like previously suggested. Let's cross our fingers. Now, I went to the repair manual and wow, you do NOT want to try and take this task on. Basically have to remove the whole dash, seats etc.


I also found two web sites that give some hints on Mold remediation in vehicle AC units. One site said mold CANT grow on the evaporator, because it is in a sealed unit. (Which seems to be the case when I viewed the illustrations in the repair unit). But, due to condensation in the vent system, mold can grow. The other site suggested mold growing on the condenser, (which is not in a sealed box) can and often does get into the air intake for a vehicles HVAC system, causing a smell.

So the solution from both sources is getting mold killing stuff into the vent system. (And on the condenser). There are a few ways of doing this.

Tonight, after you take out the cabin filter and check it for dead things, keep it out a couple of minutes. Get a can of Lysol, turn on the vhicle, turn the fan on high, Spray the can of Lysol until your finger hurts. Watch you face, don't want to blow that stuff in your eyes. While you are spraying, change the "Mode" button so the spray goes through all the vents. Feet, body and defrost.

Next, place the filter back in, or a new filter, then find the air intake from the outside of the vehicle. I think it is that grill work right under the windshield wipers, but I cant be sure about that. I could not find anything in the engine compartment which looks like air intake for the cabin, but looking at the repair manual, the whole HVAC/blower etc unit is right under those vents behind the dash.

Again, with the fan on, spray the Lysol through the grill work, (assuming I am right and that grill work is the intake.) One way to determine if I am right, turn on the fan and listen at the grill work, should hear the air going through.....in any case, that should kill the mold for now, freshen the car and your wife will love you again. Be safe.

 

[Okki]

The modern AC systems want to run constantly so it dries the air in the ducts. If your wife is like mine, she'll turn off ALL airflow. When I drove her R32 I noticed the smell and asked if she had had the AC turned all the way off for an period of time and she said about a month.

The dealer sprayed a mold removal agent into the system and told her to leave the airflow on (if anything on the lowest setting). Not had an issue since.

Our VW dealer to care of it free of charge.

Okki

 

[AddictedUSAF]

Jtraskell, Thanks man for the research on this. WHen she gets home I will look into this more and start at step one, checking the cabin air filter. I will post back this evening on my findings for sure. Thanks! Much appreciated!

 

[Jtraskell]

The modern AC systems want to run constantly so it dries the air in the ducts. If your wife is like mine, she'll turn off ALL airflow. When I drove her R32 I noticed the smell and asked if she had had the AC turned all the way off for an period of time and she said about a month.

The dealer sprayed a mold removal agent into the system and told her to leave the airflow on (if anything on the lowest setting). Not had an issue since.

Our VW dealer to care of it free of charge.

Okki

Okki, I think you are correct when using fan only and outside air. In Texas and Florida, not a good option for about 9-10 months out of the year! Don't have to run the AC all the time to get the same result. Just keep the fan on low, turn off the recirc, letting outside air in. Be safe.

 

[AddictedUSAF]

So I checked the cabin air filter today. It "looks" clean(as far as trash leaves ect...) but it defiantly has a black/grey color in the pleats and has some slight smell to it so I am going to replace it tomorrow when I run buy auto parts. Hopefully that will be all that is needed.

 

[Antman]

Maybe it's just me, but I would rather smell "pee" than an entire can of Lysol blown throughout my truck.

Guess I'm just plain weird.

 

[Jtraskell]

I agree with the Lysol smell, but, notwithstanding that Lysol was just a suggestion, ( I guess I was not clear on that) there are many other products oiut there that will kill mold without an additional oder. You REALLY do not want to "smell the pee" for any great length of time. Mold spores can be very deadly to you and your family. While the Lysol smell will dissipate in a short period of time, if the AC keeps getting used, the mold will keep building up. More and stronger pee......not good. Be safe.

 

[Okki]

if the AC keeps getting used, the mold will keep building up. More and stronger pee......not good. Be safe.

wait whaaaat???? The mold builds up due to moisture in the vents that does not dry out and thus forms a petrie-dish of growth for your mold. You want to run the AC to keep the vents and associated hoses dry.

Step 1: Kill the mold with a lysol or similar.
Step 2: Run the AC with high temp to dry out the system.
Step 3: leave the CLIMATE control turned on so it runs the AC as needed to keep the system dry (and at the temperature of your liking at the same time).

AC does more than just cooling the air; otherwise it would have been called a "chiller" and not an "air conditioner".

Not the air system specialist here, but that explanation by my dealer sounds to me like making a whole lot of sense.... I'll defer to the biologists and air-maintenance systems engineers from here forward :bigok:

Okki

 

[bofa]

This was really awful in the Xterra. It hasn't been nearly as bad in the 4R but I have noticed it periodically. Sounds like good suggestions all around.

 

[philsey]

I have heard of doing this in the past, but....my wife drives it on a daily basis and I doubt she will remember to do this. I know that works though. She said today it kinda smelt like pee. lol

I submit you have a mouse nest in your vehicle somewhere - first guess is engine compartment.

Mice pee in their nests, and they chew the $ h ! t out of everything - VERY destructive.