Vent Smell

[00Silverado4x4]

I have the dual zone auto climate control (all other info in my sig), my problem is my vents smell like a sweaty gym bag. The weird part is it only does this if I'm idling, output temp set to around 72. If I drive, or adjust temp up to 80+ or down to 60 the smell goes away. Also I checked my firewall drain, I usually have water pouring out but with the "colder" temps of Georgia all I'm getting now is cold air. I took off the overflow cap and compared the smell in there & it's not the same. I read a bunch of threads in regards to heater core problems and I don't seem to have the typical symptoms except a smell in the cab. I don't have fogging, wet floors, etc. Also I cycled through all different positions for air movement (defrost/floor/face), all worked as should. Don't seem to be losing coolant. I must be missing something so don't bash me up too badly. Hopefully someone can teach me something. I'm not pulling the core until I'm more confident that a problem truly exists, will try the bypass idea. Anyone have any thoughts?

[redjewel2ss]

 

is it recirculating air, or pulling it directly from outside?

 

 

does your truck have an AC air filter? i know some older models had them. have you checked/inspected that?

[00Silverado4x4]

Not sure where it is pulling air from, air recirculate button is not lit up. Forgive me but how do I check to verify? Also I do not have the cab air filter, discontinued prior to my model year.

[redjewel2ss]

there's a recirc button on your ac control panel that looks like this:

[00Silverado4x4]

That I did check, the light is/was not on. I just wasn't sure if there is a way to physically check.

 

BTW is that what the single zone controls look like? I'm soooo glad I got the dual zone, auto feature was just icing on the cake, wife NEVER has it set to same temps as I do.

[redjewel2ss]

lol no thats all i could find online.

 

you'll have to remove the glove box to access the little door that opens and closes for recirculating air. you could just have mold/mildew beginning to form somewhere in the ducts.

[redjewel2ss]

here's a weird video on how to remove the smell:

 

[00Silverado4x4]

Having a bad hair day, gotta be bad since I'm bald, but I assume that being stuck in recirculate would be bad? Wouldn't excess moisture still be removed by the filter drier?

 

 

Edit: Now that I've gotten some sleep I realized just how idiotic that last question sounded...sorry!

Still need to work on making sure the drain is open...hopefully tomorrow.

[waumo1]

Unless it is below freezing out and/or very low humidity, you should get condensate running out if your A/C compressor is running. If you are not getting condensate running out, you may have a plugged drain. This will certainly cause smells.

 

I don't think the 2006 had a cabin filter so that should not be the problem.

[00Silverado4x4]

Finally got the video to play. Work computer's internet stinks so had to wait until I got home. I'll look into that. Still odd about smell is only at idle & at 72 degree setting. Also I did cycle recirculate mode. Seems to be working but still going to visually confirm. However still nothing out firewall drain so what's involved to safely clear the tube?

[00Silverado4x4]

Got a chance to look at the drain. Pulled off the rubber elbow,puffed a bit of compressed air (low psi) back in & then ran a doubled over piece of safety wire in a short ways to see what, if anything, would happen. Then started up the truck ran the A/C on high fan, lowest temp setting, recirculate was confirmed to be working properly. So far water is pouring out again as it should be & even more cold air than before. Ran the truck for 20+ minutes & then went for a drive for another 30+ minutes with frequent stops to idle & system set back to Auto fan & between 72 & 75. So far so good, no more smell. I did also go under the dash and had a peek at the evaporator, or at least as much as I could see through a hole where I removed (& of course reinstalled when done) a module, looked amazingly clean considering I don't have the cab filter option. I reached in with my finger and there is some grubbiness at the bottom of the core but I have NO idea what it'll take to remove that mess.

 

Long story short, as if, I had a problem, hopefully found the fix. Thanks for all the help from everyone!