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Sour smell from air conditioner

39K views 34 replies 18 participants last post by  gspfunk 
#1 ·
We had this problem in an Xterra years ago when we were in Florida but never did in our 4Runner. We were told it had to do with the design of the system and the humidity.

Now our 2015 Grand Cherokee has a very foul, sour smell when running the A/C. It isn't a constant smell but seems to surge its funk randomly as we drive down the road. We're in Colorado, so humidity is fairly low. What's causing this and how can I fix it?
 
#2 ·
We had this problem in an Xterra years ago when we were in Florida but never did in our 4Runner. We were told it had to do with the design of the system and the humidity.

Now our 2015 Grand Cherokee has a very foul, sour smell when running the A/C. It isn't a constant smell but seems to surge its funk randomly as we drive down the road. We're in Colorado, so humidity is fairly low. What's causing this and how can I fix it?
I had a similar experiance with sour smell. There is a new cabin filter that came out recently for the problem the diesels have with diesel smell inthe cabin. The new cabin filter has charcoal in it,though intended for the diesel it works in any of the GCs. I currently have it in mine. Here is part number 68260792AA
 
#5 ·
The FRAM fresh breeze cabin air filters fit perfectly. Dunno if the '14 and '15 are the same, but the 14 is FRAM CF11183 resh Breeze Cabin Air Filter.

As others have noted, even carbon impregnated filter won't deal with dead kitty cats in the A/C.

I would start with FrigiFresh, where even in Colorado it can stink up since the outside humidity isn't what matters--it is how humid [very] it is in the innards of the A/C.
Apply at least every month or so. And if you replace the filter put a really good dose of it down into the innards with the filter out.

There are treatments that flood the A/C with a cleaning and deodorizing foam, but a good dealer would suggest FrigiFresh first.

You MAY have something in there... if you park under shedding trees or similar and don't carefully clean the underhood intakes for the A/C.
 
#6 ·
Mine has the smell since day one. Especially when I turn the AC on and off. I usually turn off the AC about a mile or so away from home so it dries out.

Not sure what's causing it, but have learnt to live with it. I would be interested in knowing how they fix it.
 
#7 ·
I have an appointment tomorrow morning to get this addressed, fix the rough shifts, and a random rattle from the drivers side dash. I'll let you know how it goes.

We leave the AC/heat on auto so I would expect the design to be able to cope with that.

For the Xterra they just sprayed something (maybe frigifresh mentioned above) into the system. That lasted for a couple of weeks until the wreak returned. We eventually stopped buying Xterras and that was a big part of the decision. Hopefully Jeep has a more permanent solution.
 
#9 ·
Still in service... Manager called to ask about how we run the system and if fresh air is used often. We typically leave the climate control on auto and it almost always shuts off the recirculation. The only time we turn it on is if there's a foul smell outside, which isn't often. Another possible issue they mentioned has to do with coolant reacting with one of the hoses but it sounds like that's far less common. At least I feel they are trying to dig into it.
 
#13 ·
So their plan today was to spray that stuff in the air box. Manager says he contacted a tech with Jeep and they make them go through different steps. First step is the spray. We drove it around for about 20 minutes tonight and could already smell the funk coming back.

The issue with the hoses mentioned above impacts Chargers and Challengers, so it is possible it's related. Or else there's just a design flaw. If anyone else is having this issue, please bring it up the next time you go in. Squeaky wheel and all...
 
#16 ·
Hey Neighbor! :)

Just an FYI. I used the AC two days ago when we got hit by the heat wave and there was no smell. Also, I have never used the "auto" feature since I never liked the way it worked.

Which year and color is your WK2?

Cheers,
-A
 
#14 ·
I'm pretty frustrated with the HVAC design. I cannot control when the a/c runs unless I take it out of auto. Every other vehicle I've owned has let me control the a/c independent of Auto setting. This makes really hard for me to turn the a/c off a few miles from home and dry off the coils. Nothing grows mold better than damp a/c coils in a warm garage. We get a funky smell in our AC as well. I changed the pollen filter and unfortunately the smell was still there. I don't like to spray perfumes because they trigger my allergies, but I have tried AC fresh in another vehicle. The trick is spraying the coils...


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#21 · (Edited)
Check for rotting leaves or debris on exterior hvac air intake, these vents are in the left rear quadrant(passenger side) under the hood. Mine gets build up of leaves on there sometimes, when they get wet or rot they can smell. Also the charcoal version of the hvac filter can help with minor smells. Jeep comes with non charcoal filter so the charcoal one is worth a try when troubleshooting but not a cure for dead animals in the system.
 
#22 ·
My 2014 was doing that any they did some kind of a star case. They cleaned the evaporator and put some special coating on the coils. Not sure what all else they did but the smell has been gone for a few months.
 
#24 ·
I checked for leaves/debris, nothing there.

I'm gonna get a charcoal filter and if that doesn't work.. maybe bomb the HVAC system with Lysol.

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I was able to have my vent system cleaned by the dealer... they had a machine that they used which made it smell like old man for a couple of days but after that the smell is gone. They had planned to replace just the filter but left the old filter out to try and make it better while they waited for the replacement.. but it still stank and I let the service manager smell. He agreed.. got the machine to clean and so far so good!!!
That was probably a month ago.
 
#25 · (Edited)
The stench in my 2014 began years ago, when the vehicle was only 6 months old, ironically approximately one week after I installed a Fram activated charcoal cabin air filter "upgrade" to reduce smells —a problem that I had never really encountered. I was surprised to start smelling "contaminated gym socks" in my Jeep for the first time ever, especially given my prior vehicles had no cabin filter and never developed this kind of smell. I quickly switched filters to another brand within about a week, but the damage was done. My WK2's HVAC was infested and smelled like that of an old Mercedes Benz. I bombed the blower with isopropyl alcohol repeatedly for months, to no avail. For years after that, any time the incoming air was humid, regardless of whether AC or heater was on, an odious stench would diffuse through the cabin.

Finally remediated it a few days ago after I removed the blower squirrel cage and cleaned it in a 10 liter ultrasonic cleaner. The ultrasonic cleaner was able to clean the fins within seconds, using only water and the physics of ultrasound/fluid dynamics. However, it was a crazy amount of work to remove and reinstall the blower (primarily one "easy to remove, impossible to reinstall" screw), so I doubt I will try that again. Instead, I will plan to avoid Fram products.

I was actually surprised; I was certain the infestation was in the evaporator coil fins and would require foam cleaning. I only cleaned the blower fins because I removed the blower to scout the HVAC system prior to foam cleaning of the evap coil and happened to notice the fins looked dirty. Had I foam cleaned the evap coils and left the blower cage uncleaned it wouldn't have remediated my problem. In that case, I probably would have assumed the foam wasn't working competently on the evaporator, despite my actual problem being in the blower.
 
#26 ·
Here's what works for me on other vehicles.

First make sure the AC condensation drain is not plugged.
When i use the AC about a few miles from parking it, i leave the AC on then adjust the temp setting to hi heat with the blower speed set to max with windows open.
All in an effort to evaporate some/most or all of the condensation left in the HVAC system

I had a slight odor coming from my XJ's HVAC system.
Here's how i got rid of it.

My XJ doesn't have a cabin filter but if there's a cabin filter i'd remove it and throw it in the trash.
When the procedure below is done replace it with a new filter.

Open the doors and roll down the windows.
Start the engine.
Set recirculate to off.
Set blower speed to max.
Get some Lysol and spray it into the outside intake vent below the windshield off and on during the entire process below.
I ended up using about 3/4 of a large can of Lysol.

With AC on adjust the temp setting to hi heat. Do this for a few minutes.
Then go through all the HVAC settings;heat, AC, upper vents, lower vents, etc. ending with the AC.
Repeat until the odor is gone.
Once satisfied run the blower a little longer to clear out the Lysol smell.

Without a cabin filter replacement, the whole thing should take no longer than a half hour.
 
#27 ·
i have this problem on my 2018 altitude. i bought this on black friday and hadn't really had too many opportunities to notice this until recently. it's starting to get warm here in phoenix, so i've been using the ac. aside from the blower/fan not being very strong, the temperature tends to dip, as if the compressor doesn't engage, and no cool air comes out when i apply the gas. after recovering from this, i notice this vinegar-like smell. i've tried many different scenarios, but no matter what i do, this drop in temperature and smell are unacceptable for a vehicle with less thank 6k miles!

any suggestions aside from taking it to the dealer only to be told it's normal? i mean, this is a really big turn off for me, especially when i'll need to be running the ac for the next 6 months straight.
 
#29 ·
Hi gust_1980,
If you change your mind and decide to have your concern addressed by your dealer, please send our team a private message and we would be happy to add an additional layer of assistance to this process!
Alex
Jeep Social Care Specialist
 
#28 ·
A vinegar smell is far different from the typical musky mold type smell AC systems can exhibit.
Could be as simple as some of the HVAC plastic housings breaking-in by leeching out oils.

But the drop in temp when the smell happens can point to something more serious.
Like the evaporator coil in the cabin is leaking freon, etc.
Though i got to be honest, i have no clue what the latest freon concoction they're using these days smells like.
There are also special oils used in the AC systems to keep the compressor lubed.
Whether they smell like vinegar, no clue either.

I'd have the AC system checked out by the dealership.
Looks like your Jeep is still under the bumper to bumper warranty.
 
#30 ·
Mine starts to stink as the air conditioner cycles from cold to not so cold. This happens about every 4-6 minutes when it is hot outside. I am told by the dealer this is a design feature and cannot be changed. I have been there 2 times. They just plug the computer in an say everything checks out OK. But for some reason have lost the ability to smell. Is Alex the Jeep Social Care Specialist still reading this board? Very frustrating. Grand Cherokee Limited 4x4, 2018
 
#32 ·
Hi bhbuilder,
If you would like to have this documented and looked into further by a case specialist, please feel free to send us a private message!
Alex
Jeep Social Care Specialist
 
#31 ·
hello all, let me provide a positive update:

per the insight provided to me by fellow member, 'jimintempe' (hope i got that right), this requires that you pay attention to things. for starters, one thing i didn't know and am still frustrated by, is the air cycle upon startup. no matter what i do, when i start ( i use remote start 99% of the time), it automatically begins with recycled air, even if the button indicates otherwise. i always make sure to cycle to fresh air upon startup, and try to maintain fresh air whenever possible. i only use recycled air when going through a particularly stinky stretch of land. i also never run the temperature at lowest setting only running it appx 73 degrees. driving in phoenix, the first thing you want to do is cool things down asap which means bottoming out the temps, but that really doesn't work any better than running it at 73 or so the entire time. long story short, in the last few months, this has really helped the smell go away. i'll still notice short bursts of warm air come through, but it's tolerable.

all in all, i can live with this system, but i honestly kinda hate that i have to work with it so much. just like the auto start, it's just another part of the daily driving routine. imho, the air conditioning is by far the weakest link for this vehicle. my wifes kia optima is far cooler, fans blow harder, and zero smell. anyway, i hope these instructions help. it might take a couple weeks of cycling through this way to get rid of the smell.
 
#33 ·
i mean, i just gave him a roadmap to alleviate a known design flaw. i went to the dealer myself and they said it was by design and provided zero insight or instruction. i learned exponentially more from fellow forum members.

jeepcares should really be called 'jeepplacates' or 'jeeppacifies' because i'm not aware of anybody who's significantly been helped by you guys, sorry.
 
#34 ·
My '14 got stanky on hot humid days the first summer I owned it. After digging through the forums I found several posts recommending using the special cabin filter designed for the diesel Grand Cherokees (Pt. # 68260792AA). It's charcoal impregnated. Six years now, and no stank. I replace every spring. If you check Amazon, you'll find other brands with charcoal. YMMV
 
#35 ·
With most vehicles, it’s due to the moisture in the system leading to mildew. Only real solution I’ve ever found is Lysol or Ozium in the vents. Run it on recirc. & spray it in the floorboard. It’ll suck it up and blow it out the vents.
If it’s still there, it will need to be sprayed near the inlet from outside the cabin.
 
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