# Musty smell from defroster vents



## 95025

I had a Volkswagen that would do this. It had a "condensation tray" that caught moisture off the AC. The tray had a "seep hole" that sometimes got plugged up, and the water would sit in that tray and get nasty.


----------



## Hardway

The condenser housing has mold in it. Some people say pour Lysol or pine sol down the intake vent below the windshield (outside). The proper way is to drill a hole in the condenser housing, then eject a chemical into the housing to kill the mold. The link explains in great detail

http://autorepair.about.com/cs/heatingac/a/aa071601a.htm

_Writer’s information is for discussion purpose only and should be confirmed by an independent source._


----------



## dinosaur1

Hardway said:


> The condenser housing has mold in it. Some people say pour Lysol or pine sol down the intake vent below the windshield (outside). The proper way is to drill a hole in the condenser housing, then eject a chemical into the housing to kill the mold. The link explains in great detail
> 
> http://autorepair.about.com/cs/heatingac/a/aa071601a.htm
> 
> _Writer’s information is for discussion purpose only and should be confirmed by an independent source._


drill a hole? how do you mean? I wouldn't be comfortable drilling holes on my suv.


----------



## Hardway

dinosaur1 said:


> drill a hole? how do you mean? I wouldn't be comfortable drilling holes on my suv.


 
read the link


----------



## dinosaur1

Hardway said:


> read the link


my question is where do you spray the Lysol, into what air intake?

I don't use the A/C in the winter time so should I turn off my heater 1 mile before coming home?

"One is to keep a spray can of Lysol in the car and spray it into the air intake one a week. That will keep the problem under control. Another is to shut the air conditioning off about a mile or so before you get to where you're going and allow the evaporator to dry out."


----------



## 95025

dinosaur1 said:


> I don't use the A/C in the winter time so should I turn off my heater 1 mile before coming home?


Actually, on most vehicles, any time you're running the defroster your AC is running.


----------



## dinosaur1

Hardway said:


> read the link


I found some info on this. Again I am not going to drill any holes though. Any work around I can try?

i. Drill a ½” hole in the plenum chamber between the blower motor and the evaporator
(fig. 2). (CAUTION: Keep drill clear of evaporator core and fan). 

ii. With the vents closed and heat fan on HIGH, insert the tool into the hole and spray
AC Odor Shield into the airstream toward the evaporator. 

iii. Use a manufacturer-approved RTV sealant to plug the hole.


----------



## Billy_Bob

There is a drain tube for the A/C which usually comes out on the passenger's side in the engine compartment.

On many cars you can see this just above where the carpeting ends inside the car on the passenger side - foot area. Looking up.

If that drain tube gets clogged, the water can't drain out!

Here is one...


----------



## dinosaur1

Billy_Bob said:


> There is a drain tube for the A/C which usually comes out on the passenger's side in the engine compartment.
> 
> On many cars you can see this just above where the carpeting ends inside the car on the passenger side - foot area. Looking up.
> 
> If that drain tube gets clogged, the water can't drain out!
> 
> Here is one...


I have to find out if mine is plugged. What's next if it is?


----------



## 95025

dinosaur1 said:


> I have to find out if mine is plugged. What's next if it is?


On my old VW, the problem was that the sound-proofing insulation over the drain nipple - located on the firewall in the engine bay - had been bumped & pinched the drain nipple shut.

Hopefully you find something like that.


----------



## dinosaur1

DrHicks said:


> On my old VW, the problem was that the sound-proofing insulation over the drain nipple - located on the firewall in the engine bay - had been bumped & pinched the drain nipple shut.
> 
> Hopefully you find something like that.


If not then I suppose I need to spray vinegar from the outside


----------



## 95025

dinosaur1 said:


> If not then I suppose I need to spray vinegar from the outside


I'm not following you on this one, sorry... 

Most vehicles have a drain that - from the outside - looks something like this (center of the picture). I'm thinking that yours is, somehow, plugged. Get it opened and you've probably solved your problem.


----------



## dinosaur1

DrHicks said:


> I'm not following you on this one, sorry...
> 
> Most vehicles have a drain that - from the outside - looks something like this (center of the picture). I'm thinking that yours is, somehow, plugged. Get it opened and you've probably solved your problem.


I hit that part. But shouldn't I spray something from the outside vent to eliminate the smell.


----------



## 95025

dinosaur1 said:


> I hit that part. But shouldn't I spray something from the outside vent to eliminate the smell.


I really don't know, honestly. They're all built a little differently, so I don't know whether you'd get anything in to where it'd do any good.

On my old VW, I actually took the tray out - partly because at the time I had no idea what I was looking for. Turned out to be fairly easy, and I cleaned it thoroughly when I had it apart.


----------



## dinosaur1

DrHicks said:


> I really don't know, honestly. They're all built a little differently, so I don't know whether you'd get anything in to where it'd do any good.
> 
> On my old VW, I actually took the tray out - partly because at the time I had no idea what I was looking for. Turned out to be fairly easy, and I cleaned it thoroughly when I had it apart.


I'll take a pic


----------



## dinosaur1

DrHicks said:


> I really don't know, honestly. They're all built a little differently, so I don't know whether you'd get anything in to where it'd do any good.
> 
> On my old VW, I actually took the tray out - partly because at the time I had no idea what I was looking for. Turned out to be fairly easy, and I cleaned it thoroughly when I had it apart.


Here is how mine looks. 

http://www.youtube.com/watch?v=SGE9YodF1iU&feature=youtube_gdata_player


----------



## dinosaur1

DrHicks said:


> I'm not following you on this one, sorry...
> 
> Most vehicles have a drain that - from the outside - looks something like this (center of the picture). I'm thinking that yours is, somehow, plugged. Get it opened and you've probably solved your problem.


I checked from the outside underneath and mine isn't clogged.


----------



## dinosaur1

I'm curious to find out why the musty smell only happens sometimes.


----------



## 95025

dinosaur1 said:


> I'm curious to find out why the musty smell only happens sometimes.


Does it change, based on where you have the main airflow going?


----------



## dinosaur1

DrHicks said:


> Does it change, based on where you have the main airflow going?


Both of our suv's have the same issue '05 Highlander & '08 Rav4. Only bad smell comes out "at times" when we have the defroster on. Same thing in the winter and summer.


----------



## 95025

dinosaur1 said:


> Both of our suv's have the same issue '05 Highlander & '08 Rav4. Only bad smell comes out "at times" when we have the defroster on. Same thing in the winter and summer.


Boy I don't know.

Have you gotten onto any specific Toyota Tech Forums? I've got an old Volvo I'm rebuilding, and I've found priceless information and advice on a couple Volvo forums.


----------



## dinosaur1

DrHicks said:


> Boy I don't know.
> 
> Have you gotten onto any specific Toyota Tech Forums? I've got an old Volvo I'm rebuilding, and I've found priceless information and advice on a couple Volvo forums.


Yep some other forums are also helpful.


----------



## Billy_Bob

The tube could be clogged up inside. There are metal refrigeration coils inside the compartment where the drain tube leads, so don't stick any sharp metal objects up there!

But maybe a length of small 1/4 inch plastic tubing could safely be inserted up the drain tube to clear any blockages up inside.

Then odors come from wetness and bacteria or mold. Get rid of the wetness and that goes away...

Car air conditioning / heating systems have two modes of operation. Fresh air or recirculate. When set to fresh air, the intake outside the car at the bottom of the windshield allows fresh air to enter the car. You may also need to crack a window to allow the fresh air to enter.

In recirculate mode, the outside vent is blocked off. The same air recirculates in the car and along with that mold and bacteria if present.

Some people ALYWAYS have it set to recirculate. Add to that a blocked drain tube, then you get a good situation for bacteria and mold to grow.

But switch to fresh air, crack a window, and run it like that for awhile without defrost or A/C on, then that will help to expel the bacteria/mold and dry out the A/C coils inside the car.

FYI - Those coils take moisture out of the air when the A/C or defroster is running because they get cold. Like a cold glass of water gets moisture on its outside.

Next "disinfectant spray" (like Lysol) kills bacteria and mold. This is sold in grocery stores in the cleaning supplies isle. 

Once the coils are dried out and the car aired out with fresh air, place it back in recirculate mode....

In recirculate mode, air enters the car's HVAC system from an intake vent under and behind the glove compartment on the passenger side.

So roll up all the windows, turn the fan on high and recirculate, then spray disinfectant spray in that area under the glove compartment. And spray entire inside of car. Then let it sit over night.

Then in the morning roll down a window. Let the car air out. And switch to fresh to air it out.

From then on switch to fresh every now and then. Fresh air is good for you!


----------



## dinosaur1

Billy_Bob said:


> The tube could be clogged up inside. There are metal refrigeration coils inside the compartment where the drain tube leads, so don't stick any sharp metal objects up there!
> 
> But maybe a length of small 1/4 inch plastic tubing could safely be inserted up the drain tube to clear any blockages up inside.
> 
> Then odors come from wetness and bacteria or mold. Get rid of the wetness and that goes away...
> 
> Car air conditioning / heating systems have two modes of operation. Fresh air or recirculate. When set to fresh air, the intake outside the car at the bottom of the windshield allows fresh air to enter the car. You may also need to crack a window to allow the fresh air to enter.
> 
> In recirculate mode, the outside vent is blocked off. The same air recirculates in the car and along with that mold and bacteria if present.
> 
> Some people ALYWAYS have it set to recirculate. Add to that a blocked drain tube, then you get a good situation for bacteria and mold to grow.
> 
> But switch to fresh air, crack a window, and run it like that for awhile without defrost or A/C on, then that will help to expel the bacteria/mold and dry out the A/C coils inside the car.
> 
> FYI - Those coils take moisture out of the air when the A/C or defroster is running because they get cold. Like a cold glass of water gets moisture on its outside.
> 
> Next "disinfectant spray" (like Lysol) kills bacteria and mold. This is sold in grocery stores in the cleaning supplies isle.
> 
> Once the coils are dried out and the car aired out with fresh air, place it back in recirculate mode....
> 
> In recirculate mode, air enters the car's HVAC system from an intake vent under and behind the glove compartment on the passenger side.
> 
> So roll up all the windows, turn the fan on high and recirculate, then spray disinfectant spray in that area under the glove compartment. And spray entire inside of car. Then let it sit over night.
> 
> Then in the morning roll down a window. Let the car air out. And switch to fresh to air it out.
> 
> From then on switch to fresh every now and then. Fresh air is good for you!


Where and how do I spray it under the glove box?


----------



## dinosaur1

Billy_Bob said:


> The tube could be clogged up inside. There are metal refrigeration coils inside the compartment where the drain tube leads, so don't stick any sharp metal objects up there!
> 
> But maybe a length of small 1/4 inch plastic tubing could safely be inserted up the drain tube to clear any blockages up inside.
> 
> Then odors come from wetness and bacteria or mold. Get rid of the wetness and that goes away...
> 
> Car air conditioning / heating systems have two modes of operation. Fresh air or recirculate. When set to fresh air, the intake outside the car at the bottom of the windshield allows fresh air to enter the car. You may also need to crack a window to allow the fresh air to enter.
> 
> In recirculate mode, the outside vent is blocked off. The same air recirculates in the car and along with that mold and bacteria if present.
> 
> Some people ALYWAYS have it set to recirculate. Add to that a blocked drain tube, then you get a good situation for bacteria and mold to grow.
> 
> But switch to fresh air, crack a window, and run it like that for awhile without defrost or A/C on, then that will help to expel the bacteria/mold and dry out the A/C coils inside the car.
> 
> FYI - Those coils take moisture out of the air when the A/C or defroster is running because they get cold. Like a cold glass of water gets moisture on its outside.
> 
> Next "disinfectant spray" (like Lysol) kills bacteria and mold. This is sold in grocery stores in the cleaning supplies isle.
> 
> Once the coils are dried out and the car aired out with fresh air, place it back in recirculate mode....
> 
> In recirculate mode, air enters the car's HVAC system from an intake vent under and behind the glove compartment on the passenger side.
> 
> So roll up all the windows, turn the fan on high and recirculate, then spray disinfectant spray in that area under the glove compartment. And spray entire inside of car. Then let it sit over night.
> 
> Then in the morning roll down a window. Let the car air out. And switch to fresh to air it out.
> 
> From then on switch to fresh every now and then. Fresh air is good for you!


So I'm understanding that I should avoid recirculate mode? I like to use it when stuff from the outside stinks like a car exhaust, skunk, etc....

To be honest the inside musty smell comes as goes. It hasn't smelled now for about 3 weeks.


----------

