I had a weird vinegar smell coming from the AC on my 2017 Optima. Changed out both the engine and cabin filters which helped - until a few weeks later after it rained pretty heavily. So I looked at other options and found this Armor All Fresh FX vent and duct cleaner deodorizer spray. Had great reviews and figured I’d give it a shot before bringing it in to someone. Well, it got rid of the smell. However I began to notice that running the air and AC now caused this awful tickle / tingling in my throat. Well that turned into a cough, which turned into wheezing, which turned into me borrowing my girlfriends car just so I could recover before an upcoming event all in the course of about three weeks. Girlfriend noticed it happened to her as well when driving it to work the last few days.
I’m bringing it in to the shop tomorrow to see what can possibly be done but I’m wondering if anyone has any ideas of what the hell happened and what I could do to fix it? The instructions say to spray a little less than half the can into the fresh air intake vent with the AC on high and let it run for like 10 mins with the windows open, then go in and spray a bit into the inside vents. I’m wondering if whatever was in the spray loosened up any dust mold and dirt inside and now its just blowing out of the vents every time I turn it on. That or the chemicals in it are sitting on some part of the system and are getting “reactivated” with any moisture when I turn on the air or
AC. But, I really don’t have a good understanding of how the AC system works and whether it would be either of these things. Any help you guys can give me will be very much appreciated. I just want to be able to drive my car without hacking up a lung again.
i would make sure the evaporator drain isn’t clogged, when the car is parked with the AC running do you see a puddle of water under the car? If not you need to unclog the drain
Sounds like antifreeze vapor is making its way into the cabin by way of a leaking heater core. The armor all story is just a coincidence.
Could be either of the above. I would verify the AC drain is open, usually it is located on the firewall on the passenger side of the vehicle. It might show the location in your owners manual or there could be a YouTube “how to” video.
I would put in another new cabin air filter.
When not driving try to leave it in the sun with the windows open a few inches and the AC set to vent position.
Keep an eye on the radiator coolant level, if not losing coolant that would pretty much rule out heater core leaking.
All good advice and a clogged AC drain, mixed with accumulated “summer schmutz” and left to ferment may have resulted in your first vintage of Chateau KIa, creating in your first odor.
“Cleaning” it with half a can of deodorizer spray may have stopped the fermentation and covered up the odor with perfume but if the water isn’t draining, you simply added some chemicals to the ferment, which have given me the same reaction you describe.
Blow out the drain hose, vacuum out the air intakes, clean out around your air filter and carefully flush out the system with plain water, (being sure the water continues to drain out the AC drain hose) may be the solution.
Good ideas about checking the drain blockage.
Just few more words on odor control.
Myself, I had much better success with a manual scub&wipe, then using the ionizer / ozone generator over 2-3 days in a garage rather than “odor eliminator” chemicals.
The former method really destroys the odor source, the later bonds to the odor source and adds perfume, resulting in some sickening combination.
I was just recently cleaning 14-years-old car previously owned by an Indian guy, at first I thought it would take foever to remove the incense-like smell, but after having car in the garage for 3 days with an ionizer running inside and windows 1/4 open, the smell is completely gone and the car is “odor neutral”.
While it’s not impossible, a leaking heater core in a 2 year old car is not likely.
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Thanks to everyone who has responded so far. It’s been very helpful. One thing to add: I noticed driving it to work this morning - even with the windows down and the vents set to close I got the same reaction. How could that be?? Just due to it sitting with the windows closed/vents open all night?
Possible . You might try calling a few detail shops and see if one has experience clearing the air vents and removing any substance from surfaces that can cause this problem.
The standard cabin filter is just paper. I believe there are available charcoal filters, and I think I saw them at Walmart. That could help . Any armor all product used inside a car irritates me.
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I’m allergic myself and I pretty much recognize the symptoms you describe.
In my case, I was allergic to the dust and disintegrating paper on the walls of my garage, found it shortly after buying our last house.
What helped me was to prime the [unprimed] drywall and to make a cleaning session in the best respirator I could afford.
Right after I was done, I was able to get into garage and not to get allergy symptoms in under a minute any longer.
At this point, assume you’ve got the allergy to the thing you treated your car with.
Your best strategy is avoidance: by cleaning the car interior/vents as much as you can… or maybe even trading the car if you can not get it to the point where your symptoms are not showing up anymore.
Allergy never gets better, only worse, so don’t try to “adjust to it”.
Another hint in this direction: some people are super-allergic to the mildew spores, so if we assume your heater/AC coil drain system is clogged, it would make a moldy mess there quite fast.
Vinegar smell is often a sign of mildew growth. As others have suggested, check for a clogged AC drain. Also, do not use recirculate mode unless you’re trying to block something outside from getting in (i.e, you drive through smoke from wildfires). Recirculate can promote mildew growth.
Remove the cabin filter. Turn your climate control to bi-level, full heat, maximum speed fan. While the heater is on blast, get a mold-killing spray (it’ll probably come in a pump spray bottle) and spray a lot of it down the vent in front of the windshield. Alternately you can use a can of Lysol, but that’s gonna have its own bad smell for awhile.
After the bottle/can is empty, let the heater run for half an hour to dry everything out. Then put a new cabin filter in.
If that doesn’t work, you may have to have it professionally attended to.
It can also be mouse urine. Any mouse activity will be pungent when the humidity is high as well…here’s a fun fact- I had one car that was acrid when it rained or was high humidity. No sign of mouse nests inside car or ducting. Turns out, they built a nest in the hood. Not between the insulator and hood, IN the hood through quarter sized holes between the hood top sheet and structural channels. This is positioned right over the fresh air intake vent…
Yeah very true.That must’ve been a fun one to clear.
And they will build anywhere. I had a car parked in the grass for awhile, waiting for an engine swap. When I pulled it into the garage to start the work, I just couldn’t figure out where the dead-mouse smell was. I looked everywhere.
It’s a good thing the fuel tank was leaky, because when I dropped the tank to replace it, there on top of it was the mouse nest, full of dead baby mice. I figured they expired from the gas fumes.
Well… Lets not overlook the fact that Armor All smells absolutely horrible… This is a fact. I cannot stand the stuff and havent used it in decades however I can tell in an instant who does use it. Ugh…its genuinely awful and a poor product all around.
It may simply the putrid smell of this product that you need to contend with…
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This wasn’t the “let’s make the car shiny” Armor All. It was Armor All’s interpretation of potpourri spray.
… Which probably also smells awful, but at least it won’t make your steering wheel slippery when the idiot at the carwash lathers it on. 
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Yeah, used that stuff once on the vinyl seats of an old Nova and every left turn, slid onto my girlfriends lap.
Got my face slapped a lot. 
What’s a good method of getting inside the vents, if at all possible? Considering I sprayed it in there directly as well If there’s a way to wipe that part down I’d like to try and do so
I can not imagine the way to safely get inside vents to clean the stuff.
Disassembly is way too complicated and expensive as a result.
It was suggested above to clean the AC and heater core with some cleaner spray, this is where majority of the “stuff” would end up clinging, but I’m a little bit concerned with any kind of strong chemical there, as these are aluminum and harsh chemicals can damage it.
I had an experience helping a friend of mine to remove mildew from his home HVAC coils, we used a garden sprayer and some cleaner specifically labeled as aluminum safe and for use in HVAC cleaning.
Yes, it made a world of difference to remove a moldy smell he had from the prior house owner ho ran the system with no filter, but to compare to the car, it is much more accessible and easy to work with.
That thing makes me feel I’ve got allergic reaction seconds after I smell it.
Ugh… awful…