musty smell after turn off AC...

[LV426]

Does anyone have an idea on whether or not the evap coil is easily accessible from the inside of the cabin so one could possibly blast some Klima-Cleaner into it? I've been through this before with Audi & VW and I could get to those through the filter access. I haven't poked around behind the glove box yet, just trying to go in with an idea.

This is more pronounced with the start/stop and filter changing does nothing, dealers telling people that should know better....

 

[SpookyWatcher]

Welp... Lump me in with this same problem. Bought brand new end of Dec 2020. Porkchop lives in my climate controlled garage. It seemed to be after using recirc ac? If I used fresh air ac then turned off ac I don't remember getting it. Which is why I haven't seen it till now? Cause haven't needed to use recirc with the nice wx.

But with the hot spell a couple of days ago I used the recirc ac and max to cool down after sitting in a parking lot for a couple of hours then after turning off ac it smelled.

 

[LV426]

I can't imagine how they put all this fancy tech into this truck and then didn't take into consideration that the evap could get nasty and the start/stop would "enhance" it.
BTW, i've let it sit for 20 min 2x with the heat full blasting the last few days in an attempt to dry out the coil and that might be making an improvement (cheap/temp fix). Still need to hit it with Klima-Cleaner.

 

[DevinB]

There's something to what others are saying on here about not running Recirculation (or making sure it's off before you turn your vehicle off) all the time and/or running dry air through your system with the AC off before turning off your car/truck. By nature the Recirculation setting seals off your vents from the outside and when you shut the car/truck off, it creates a damp/enclosed space that warms up back up as the truck sits there.

Don't have my truck yet, but I had this issue on my 2014 Chevrolet Impala. Sour milk smell whenever I turned the car on and started the AC after sitting there a bit. And I lived/live in a super dry desert area, that doesn't necessarily help. Hot garages with poor ventilation also make it worse. (heat + trapped humidity = stank growth). When you park inside an enclosed garage with no natural ventilation, the residual heat from the engine warms up the garage even more...and also the dark, wet little stank-cave in your AC system. Wreaks havoc. There was actually a TSB for the Chevy Impala for it, and they did it for me...helped a lot...didn't completely solve it but made it way better. After 5 minutes or so of sitting, the Recirculation vents open (if closed) and a blower runs for a few minutes to dry things out. RAM could do something similar.

 

[DevinB]

oh and the 'dirty air filter' excuse is only RARELY the culprit. It's usually the 1st suggestion from the manufacturer or the dealer though to get you to shell out X bucks for an unnecessary new one. I went through 3 before I had the blower TSB done. Then, I didn't change my filter accidentally for like 3 years....thing looked disgusting but I never smelled a thing.

The article that silver64 posted earlier at https://carcarecamp.com/maintenance/best-ac-evaporator-cleaner-for-cars/ nails it. The relevant snippet is below.


---------from link above---------------------

How to Prevent Bad Odor from Your Car’s AC​

Don’t worry, you won’t have to keep buying evaporator cleaners every summer if you prevent the bacteria from making a home for themselves in your car’s AC system.

1. Make sure the drain tube isn’t clogged. If your drain tube is clogged, you will have to use evaporator cleaner’s that are designed to be sprayed through the drain tube. Spray the cleaner through the drain tube and let it soak for 5 minutes. Make sure you don’t remove the spray nozzle from the drain tube or the contents will spill prematurely. If you’re unsure how to clean the drain tube and don’t want to risk damaging the evaporator – get your mechanic to do the job for you.
2. Let your evaporator dry out. Before the end of your trip, turn off the AC and let your blower motor dry out the moisture for at least 10 minutes. Some cars have this feature and do it automatically approximately 30 minutes after you shut off your engine – so don’t worry if your car turns on the blower motor out of nowhere, it’s probably not possessed.
3. Clean your evaporator with a special cleaner. Spray the antiseptic evaporator cleaner directly onto the evaporator or onto the vents. AC evaporator cleaners are designed to kill all the bacteria and mold from your car’s AC system.
4. Replace your cabin air filters. This is often overlooked but replacing your cabin air filter makes a big difference. The cabin air filter is designed to capture and prevent dust, pollen, and other contaminants from entering the cabin. Since the filter collects all kinds of contaminants it could act as a source of food for mold. For best results, replace your cabin air filter with an Active-Carbon air filter as they are considerably more effective at purifying the air and preventing bad odor

---------from link above---------------------

 

[silver64]

Ok lets do a little history here. AC has been around for a long time. Even though it has been refined over the years it still basically works the same.
The issue of drainage of the condensation is not rocket science so I am not sure why this truck seems to have so many complaints if the fluid is draining properly there should be no issues. With past vehicles over time the drain tube would get plugged up and cause this condition. Getting under the car with a wire hanger to ream out the tube fixed the problem. The drain on this truck seems very difficult to find and it seems to me that the drainage is the issue for these trucks. Does anyone actually know where the drain is on these trucks? If so please take a pic and post it.

 

[LV426]

Well, I was able to blast some Klima-Cleaner in the condensation drain today, no way to get in safely from within the truck with disassembling things.

See pics, drain is passenger side & fairly easy to get to (within engine bay). I did short bursts multiple times, kind of listen to when it sounded like it was filing up. I split the can between the truck and my wife's VW. Didn't leak inside at all, Hope it works....

 

[joemo]

Well, I was able to blast some Klima-Cleaner in the condensation drain today, no way to get in safely from within the truck with disassembling things.

See pics, drain is passenger side & fairly easy to get to (within engine bay). I did short bursts multiple times, kind of listen to when it sounded like it was filing up. I split the can between the truck and my wife's VW. Didn't leak inside at all, Hope it works....

I live in Florida and have 55xx miles on my truck. I just experienced this 2 days ago. I am curious if this helps you. I had this issue with my Tesla Model 3 and I just needed to spray the evap coils down with some foam thing I bough.. But it came back after time.. So following this and wondering if what you did helped.

 

[LV426]

I used this stuff before in my Audi and it did actually work. My wife's VW was getting the smell but I was sort of dismissing it, now that my truck has it I was like, we need to do something now (lol). Anyway, I'm not sure if it worked yet, but ill update in a few days. I'm 100% confident it will eventually come back though, its just something we have to deal with in warm climates.

 

[njt07]

After looking at mine and spraying the drip tube and fresh air intakes with disinfectant, I thought of a question for the more technically inclined folks. Is the fact that the drip tube is facing “into” the wind (ie forward) allowing the air coming into the engine bay to blow the water back into the evaporator/ac unit? Would putting a flexible hose that points down help prevent this?

 

[LV426]

It does seem like a weird & kind of a lazy way to do it. Most I've seen are pointing down or have a flexible drip tube. I'm not really sure of the logic of this location especially since it drips directly on the frame. Seems like an afterthought or the engineers were just like whatever.

It very well could be not draining properly and that condensation water just sits in there and festers, gets stagnant and then we have the wonderful smells circulating in the truck. I wish I could see the other side of the drain on the inside and see what the design looks like.

 

[silver64]

After looking at mine and spraying the drip tube and fresh air intakes with disinfectant, I thought of a question for the more technically inclined folks. Is the fact that the drip tube is facing “into” the wind (ie forward) allowing the air coming into the engine bay to blow the water back into the evaporator/ac unit? Would putting a flexible hose that points down help prevent this?

Even a 45 or 90 would probably be an improvement.

 

[silver64]

It does seem like a weird & kind of a lazy way to do it. Most I've seen are pointing down or have a flexible drip tube. I'm not really sure of the logic of this location especially since it drips directly on the frame. Seems like an afterthought or the engineers were just like whatever.

It very well could be not draining properly and that condensation water just sits in there and festers, gets stagnant and then we have the wonderful smells circulating in the truck. I wish I could see the other side of the drain on the inside and see what the design looks like.

Use a camera probe that fits into the tube.

 

[LV426]

Well I can confirm that the smell has completely gone away (for now) in both vehicles. The truck vents discharge clean/unscented smelling air with the a/c on or off. When I drove in this morning, no stink when the engine stopped at a light.
I would say that blasting cleaner into the drain has worked in my case, I ordered another can just to have because sometimes this stuff is out on Amazon.

 

[njt07]

Ihad a can of disinfectant spray so pulled out the airfilter and sprayed that and spray a bit int9 the drain tube and on the vent intakes under the windshield (Those ARE the vent fresh air vents right?).

No smell on day 2 after doing that.

 

[LV426]

Ihad a can of disinfectant spray so pulled out the airfilter and sprayed that and spray a bit int9 the drain tube and on the vent intakes under the windshield (Those ARE the vent fresh air vents right?).

No smell on day 2 after doing that.

That may work or be very temporary. The smell everyone has (for the most part) is coming from a funky evaporator coil and whatever it sits in. It needs to be cleaned/disinfected.
Foaming cleaners work the best in this case, the trick is to find a spot to pump the stuff in were it "fills up" and soaks the coil with cleaner and does not leak out all over inside the vehicle.

 

[silver64]

That may work or be very temporary. The smell everyone has (for the most part) is coming from a funky evaporator coil and whatever it sits in. It needs to be cleaned/disinfected.
Foaming cleaners work the best in this case, the trick is to find a spot to pump the stuff in were it "fills up" and soaks the coil with cleaner and does not leak out all over inside the vehicle.

If there is no condensation leaking into your vehicle today there is really no reason to think that a cleaner would cause it to happen. I would say that its possible that spraying the cleaner down the cowl would get it to the coil but you would need to confirm that by checking whats coming out of the drain hose. You also may be able to spray cleaner down the intake where the cabin filter is since its closer to the coil.

 

[LV426]

From what I could see, there is no way to safely access the coil from within the truck without removing parts or "opening a can of worms"... Coil seems to be way left of the filter opening with blower below it (I think). Honestly I took one look for a few seconds and was like nope... try the drain. Logically, the evap coil should be in close proximity of the drain anyway.

I didn't want any of the stuff leaking onto other parts, motor, sensors, etc... I have no idea what the hell is in there. I also don't think they make these systems completely watertight, my old Audi must have had seems and the stuff leaked out from somewhere and was dripping on the floor, others have reported the same. My goal was to get the cleaner on the coil and nothing else.

In my younger years I was a residential A/C tech for a while so I used to pull coils and clean them often. I have a general idea on what's going on with this problem, it just surprises me that they still cant get it engineered better.
I'd like an explanation on why the fan can run for X amount of minutes after vehicle shut down to aid in drying out the coil...

 

[Neurobit]

Here's the procedure for doing this, although I like @LV426 solution a lot better.
(cool handle btw. I'm an Alien nut as well)

 

[392DCGC]

Well, I was able to blast some Klima-Cleaner in the condensation drain today, no way to get in safely from within the truck with disassembling things.

See pics, drain is passenger side & fairly easy to get to (within engine bay). I did short bursts multiple times, kind of listen to when it sounded like it was filing up. I split the can between the truck and my wife's VW. Didn't leak inside at all, Hope it works....

Does the cleaner itself have a scent/odor? Hopefully not, but may not be avoidable...