Mildew Smell

Mildew smell coming from vents in ‘01 tundra. I’ve never replaced the interior air filter, how do i? Is this the reason it smells like this? Never replaced before. Grandfather kept good condition of truck. Everything works fine but time to replace some parts.

 

I dont think first gens have a cabin filter.

 

They don't. OP, I would suggest accessing the venting system through the outer screen at the windshield and inside at the blower motor and condenser area and checking for decomposing matter. After that, bomb it with a Meguiars Air Refreshener or ArmorAll's version of it. While you're checking the vent system I would also look for evidence of water leaks inside.

 

Never had to use it, but I think they make a cleaner spray for the coils that gets rid of the smell, might be something to look into. I also recall some people here running the outside air instead of Recirc for awhile after turning off the AC before getting home. Seems to dry the coils eliminating some of the mold and odor to build up.

 

It comes from keeping your airflow on recirc. Here is what I would do. Get a can of ozium, the small one will do. Its at autozone or wally world. Put your air on full blast and lower the windows, fresh air mode. Step out of the truck and spray it in short bursts at the cowl in front of the passenger side, right below the windsheild. Stick you head in the window, smell ozium? Good. Let it run a few minutes, stay out of the truck.

Next, flip it on recirculate mode, shoot a few quick bursts under the glove box and let it run like that for a few minutes, again while you aren't in the truck. Flip back to fresh air mode after that. If you sprayed too much you'll probably need to drive with it on fresh air mode for a day and windows down. Just a little bit will do.

It may smell medicine-ish for a day or two but that goes away. What you are smelling is bacteria, ozium will destroy it. From now on, avoid the recirculation mode. If you must use it, flip to fresh air mode a few minutes before turning the air off. This will help keep the air track dry and keep the funk away.

There is no cabin air filter on your truck.

 

You make a great point re: moisture build-up on the coils and the potential after-effects of it, especially in a more humid environment. We don't typically have those conditions here in the desert so it's easy to forget the possibility.

 

There's a thread on here somewhere where they discussed a coil flush. There's a cleaner made specifically for this. I believe they were using the condensation drain line as the access point.

 

^ This is the answer..
I had the same issue with my 2005.
If I drove it somewhere and stopped, having it on recirculate, it would smell like mildew when I got back in it.
If I drove it somewhere and made sure the last few miles were on fresh air, it would NOT smell like mildew when I got back in it.

SO what I learned, don't use recirculate unless you really have to.
I rarely ever had the 2005 on recirculate, unlike my 2014 and uses it as a startup default.
If you do use it, make sure you select fresh air a few miles/minutes before your destination to let it air out.

My favorite service advisor told me that was the issue on my 2005 (around 2010 when I asked her).
Never had the mildew smell after taking her advice...

 

$30 GENUINE TOYOTA APPROVED S.E.T. SERVICERITE AC EVAPORATOR REFRESH KIT 00053-00008

https://www.amazon.com/GENUINE-APPROVED-SERVICERITE-EVAPORATOR-00053-00008/dp/B07D3B5JTZ

 

Friend of mine kept having this issue, and it was two-fold. One, her AC condensate drain kept clogging up, which made water pool and dump into the passenger floorboard. High humidity + sealed and lit area = mildew and mold growth. Two, she ended up with slime mold and mildew overgrowth because she always ran recirc through the periods where this happened a couple times. First times, I just cleared out the obstruction. It wasn't until I used a specific product which safely foams the coils and melts away the stuff in the system all of this went away. The product is called Frigi-Clean and I talked about this more here. Cheapest place to buy the full kit is fleabay, $37 right now if you search for item 294274749804. There are plenty of cheaper products to safely foam out your system which are much cheaper. I just prefer BG's Frigi-Clean kit. I haven't figured out a good place to tap the evap coil box on our Tundras to install the fitting for routine future treatments though, so don't ask me about that.

I would warn you, though: There are several places for these trucks to leak into the cab. There's a dedicated thread in the top 'sticky' section of the forums if you scroll down in that top post list. look for 'definitive leak thread'. It'll give you a lot of things and places to check. I'd start by directly touching the carpet on the floorboard in several places. Push a paper towel hard into the floor in the corners and middle of the carpet to see if any water pops up. Repeat in the rear cab corners and the rear floor board corners. These are the common water pooling points if you're leaking. Good idea to do this after a heavy rain, or after a trip through the carwash (although I'd also warn you to never use automated car washes, that's another story entirely...)

 

Oh - and a good way to know if this is just your AC system or if it's a long-term water leak: If you can see dark grey, dark green or similar spots on your seat belt straps, you probably have an interior leak that's been going on for a while. Seat belts are covered in 'food', like, human skin, organic rub-off from your hands, etc. If you have a high humidity situation in your vehicle like a cabin water leak, even in the slightest, once the humidity in your vehicle exceeds 60-65°F pretty regularly, mold and mildew will start growing on the straps. Once it's in there, it's damn difficult to get rid of too, even after using products like Microban.

Pics of a really severe and really mild cases:

 

As someone who has purchased many used vehicles, sometimes they just stink. Of course finding the root cause is the best case scenario but sometimes just the age of the vehicle is the culprit. I've tried air freshener's, air sponges, sprays, cleaners etc but it was only temporary fixes. If you have a smell that you cannot find, an Ozone Generator is the only way to go. A few years ago, I had purchased a 2003 Tahoe from my neighbor and it had stale type of smell to it. Not sure if it was smoke or something else, but everything I tried would not get rid of the smell. I started googling things and found this:

$100 Enerzen Ozone Generator 60000mg Industrial O3 Air Purifier Deodorizer (60000mg - Black)

https://www.amazon.com/Enerzen-Comm...eywords=ozone+generator&qid=1629392290&sr=8-3

This is the ONLY thing that killed the smell permanently. I set the generator on the center console with the vent facing towards the rear of the truck. I let it run for one hour with the vehicle off and windows up. I then started the vehicle, turned the AC on full blast (with recirculate on) and let it run for another thirty minutes. After that, I rolled down all the windows and let it air out for an hour. The first test drive, the car kind of had a chlorine type smell to it. Not in a bad way but you can definitely smell the difference instantly. The next day, the car smelled like nothing, literally blank. I popped in my favorite air fresheners (I'll never say which ones I use, it's a secret) and the smell never returned. I want to say I paid $99 for it but they have since come down in price. For $59, you can't go wrong and it has multiple uses. Top it off with a can of BG Frigi-Fresh or Ozium in the vents below the windshield cowl and you are set. I am going to be hitting the Tundra with it again as someone recently had a little too much on Friday and decided to share their lunch in the back seat...

 

Those ozone machines are also what professional car detailers use. Nice call @SouthPaw

 

Well shoot! Call me a professional lol! I do take detailing my car serious so I have some pretty neat gadgets but the ozone generator is one of my favorites.

 

I have one of those too -- I also got it on Amazon. (might have been $89 at the time) Let me tell you, that may be the best $89 I ever spent. That thing really worked to clean the smoke smell (previous owner) from my wife's car. I also used it to de-stink a recliner: tented it with plastic, and let it run for a few cycles. Amazing!
It smells like water when it's done -- like just after it rains. I find it kind of pleasant.

 

Plans are to do something similar to what @BobTTundra did !

The 6 Million Dollar Tundra Revival Story

 

That's actually a really clever idea, using a hole saw to open it up. You could probably go to McMaster-Carr or Fastenal and find a perfect fitting plastic or rubber plug to cover the hole. I may need to marinate on that one for a bit. Aggressive, but ...

 

I wonder if something like this can reach up through the blower motor hole, just to suck up the leaves and stuff.

 

They do get some pretty raunchy smells out. Tomorrow, we will be putting it to the test. One of my drivers complained this week that his AC wasn't working and that his truck smelled. When we looked it over, we found a mouse nest and two dead mice stuck in the cabin air filter. Let me know tell you, dead mice stink but they REALLY stink 95*+ weather. I am not sure how long they were marinating in there but it's pretty bad. We will be running a good cycle on it tomorrow. Picture for proof.

 

Dude was breathing dead mice particles...

 

That's exactly what I did. I have a similar reducer, then duct taped a piece of vinyl tubing to the end. I was able to reach in through the resister hole and clean out all the debris.

 

THIS!!! Old Gen 1 Toyota Mechanic (back in the day) cautioned constantly about the recirc function and how it traps moisture in the system.

 

Careful with this product. It works great and I used them for quite a while, until I got a bad batch. It left white film all over the inside of the interiors of two of my trucks. I’d put them in the night before so I didn’t see it until the morning. It was a major bitch to clean it up.

 

This right here is exactly what I would do. Just be careful and make sure you ventilate the vehicle thoroughly before getting back in it. Both an ozone generator and Ozium are great products, just be careful not to breathe in any of either.

An ozone generator is a great thing to have anyway. Works wonders for mildew, smoke, or flooding smells in a home.

 

Definitely is. EPA of all sources has a really good write-up on pros/cons/risks/results etc. of using ozone generators for such purposes over here: https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-are-sold-air-cleaners