0Mike Yeager@Eastcoast Performance

Hey guys, I need someones help with a problem with my 2006 C6 Z06...

I have a terrible smell that comes out of the vents when the AC is turned on when I start the car...It will last a couple of minutes...Its does Not smell at all during winter time with the heat on...So whats up with this..??

I have changed the cabin air filter, sprayed Lysol in the area where the cabin air filter goes and these things have not helped...I will say this, the cabin filter that I removed was super dirty, really bad....

Has anyone else ever experienced thisproblem and how did you fix it???

Hoonose

There is an expensive dealer fix. But if you get into the habit of turning off just the snowflake, and let the fan run a few minutes before shut down that helps alot.

hawkgfr

Make sure you aren't continually running the AC in recirculate...I think its caused by condensation in the vents that gets musty over time. Using the air longer and making sure its used in the fresh air mode especially before you shut the car off helps. By summer it will be gone. Just keep using it but not in recirculate.

cclive

I knew I would find that you were in a humid place....couldn't get this to happen in Utah if I tried....just too dry.

BLACK 08

Try BG FrigiFresh. You spray it in the air vent at the cowl with the cabin filter removed and run the AC for a few minutes. Cleared mine right up as well as my wifes car too.

http://www.bgprod.com/products/climatecontrol.html

CroOrange

There are two things to do:

1/ Activate the after blow on the A/C and make sure you use the A/C on auto as often as possible.
2/ Disinfecte the A/C per GM instructions.

I'm sure someone can post up the process, if not I will scan it and hook it up.

a++ Cedric

DarkFox1

Got this problem too.. a/c smells like a wet dog when I turn it on. I've just been putting up with it.

CroOrange

Well I activated the after blow option with my Tech 2 and the smell is now gone.

I need to desinfect the A/C to really make it clean, but haven't had the time.

a++ Cedric

LS WON

I had this same problem in the earlier years of ownership of this car and was always putting it in recirculate mode to get colder air. I sent it to dealership to remedy this but odor came back. I sprayed the cabin filter. I now use the air cond. not on recirculate and sometimes just use the fan and more often now I just don't use the system. Now the odor is gone. When it used to stink it stunk bad.

08vycpe

There is a TSB concerning this. Turning on afterblow is a good idea or, as suggested, running the fan with the snowflake button off to turn off the compressor.

Remember turning on afterblow will help prevent future odors but you might want to consider doing the cleaning per the TSB. Warranty will cover this but if you are out of warranty most dealers will turn on afterblow as a courtesy. Chevtech posted the Tech II procedure for turning on afterblow. See procedure following TSB.

TECHNICAL

Bulletin No.: 99-01-39-004C

Date: June 12, 2009

Subject: Air Conditioning Odor (Install Evaporator Core Dryer Kit and Apply Cooling Coil Coating)

Models:
1993-2010 GM Passenger Cars and Trucks (Including Saturn)
2010 and Prior HUMMER H2, H3
All Equipped with Air Conditioning

Supercede:
This bulletin is being revised to add the 2009 and 2010 model years. Please discard Corporate Bulletin Number 99-01-39-004B (Section 01 - HVAC).

Condition

Some customers may comment about musty odors emitted from the Heating, Ventilation and Air Conditioning (HVAC) system at vehicle start-up in hot, humid conditions.

Cause

This condition may be caused by condensate build-up on the evaporator core, which does not evaporate by itself in high humidity conditions. The odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment.

There are several other possible sources of a musty odor in a vehicle. A common source is a water leak into the interior of the vehicle or foreign material in the HVAC air distribution system. Follow the procedures in SI for identifying and correcting water leaks and air inlet inspection.

The procedure contained in this bulletin is only applicable if the odor source has been determined to be microbial growth on the evaporator core inside the HVAC module.

Correction

Many vehicles currently incorporate an afterblow function within the HVAC control module software. The afterblow feature, when enabled, employs the HVAC blower fan to dry the evaporator after vehicle shut down and this function will inhibit microbial growth. Technicians are to confirm that the customer concern is evaporator core odor and that the vehicle has the imbedded afterblow feature, as defined in the SI document for that specific vehicle model, model year and specific HVAC option. Refer to SI for enabling the afterblow function. Vehicles being delivered in areas prone to high humidity conditions may benefit from having the afterblow enabled calibration installed prior to any customer comment.

Important
If the vehicle is not factory equipped with the imbedded afterblow enable feature, it may be added with the Electronic Evaporator Dryer Module Kit (P/N 12497910 or AC Delco 15-5876).

Important
When installing the Electronic Evaporator Dryer Module, you MUST use the included electrical splice connectors to ensure a proper splice. Complete detailed installation instructions and self testing procedures are supplied with the kit. If necessary, the Electronic Evaporator Dryer Module may be installed underhood if it is protected from extreme heat and water splash areas.

To immediately remove the evaporator core odor on all suspect vehicles, it is necessary to eliminate the microbial growth and prevent its re-occurrence. To accomplish this, perform the following procedure:

Vehicle and Applicator Tool Preparation 1. The evaporator core must be dry . This may be accomplished by disabling the compressor and running the blower fan on the recirc heat setting for an extended period of time.

Note
Compressor engagement will cause the evaporator core to remain wet and will prevent full adherence of the Coiling Coil Coating to the evaporator core surfaces.

2. Verify that the air conditioning drain hose is not clogged and place a drain pan beneath the vehicle.
3. Place a protective cover over the carpet below the evaporator core.
4. Remove the cabin air filter, if equipped, and cover the opening prior to applying the Cooling Coil Coating, as the product may clog the filter. If the cabin air filter appears to have little or no remaining life, suggest a replacement to your customer.
5. If the HVAC module has a blower motor cooling tube, be careful NOT TO SPRAY THE COOLING COIL COATING INTO THE BLOWER MOTOR COOLING TUBE .
6. Attach the Flexible Applicator Pressure Spray Tool (J-43810-20A) to a compressed air line operating at 586 kPa (85 psi) to 793 kPa (115 psi).
7. Shake the bottle of Cooling Coil Coating well. Screw the bottle onto the cap on the applicator tool's pick-up tube.

Note
The pick-up tube is designed for 120 ml (4 oz) and 240 ml (8 oz) bottles and should coil slightly in the bottom of a 120 ml (4 oz) bottle.

8. Use one of the following three methods to apply the Cooling Coil Coating.

Important
If the Pressure Applicator Spray Tool (J-43810-20A) is not available, the Cooling Coil Coating is also available in an aerosol can (P/N 12377951 (in Canada, 10953503)).

Application Through Blower Motor Control Module Opening - Remove the blower motor control module (blower motor resistor). Refer to the applicable procedure in SI.
- Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface.
- Apply the Cooling Coil Coating directly to the evaporator core through the blower motor blower motor control module (blower motor resistor) opening.
- Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces.
- When the application is complete, install the blower motor blower motor control module (blower motor control module).

Application Through Blower Motor Opening - Remove the blower motor. Refer to the applicable blower motor removal procedure in SI.
- Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface.
- Apply the Cooling Coil Coating directly to the evaporator core through the blower motor opening.
- Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces.
- When the application is complete, install the blower motor.

Application Through a Hole in the HVAC Module - If neither of the two previous application methods are available, it may be necessary to drill a hole in the HVAC module.
- Locate an area of the HVAC module between the blower motor and the evaporator core. Drill a 10 mm (3/8 in) hole in the HVAC module. Use caution to keep the drill clear of the evaporator core and the blower motor fan.
- With the air distribution vents closed and the blower motor fan speed on HIGH, insert the applicator tool into the hole and spray the Cooling Coil Coating into the airstream toward the evaporator core.
- Use a GM approved RTV sealant to plug the hole in the HVAC module.

9. After the Cooling Coil Coating application is complete, start and run the vehicle for approximately 10 minutes, with the compressor disabled, HVAC mode set to Recirculate/Max, heat set to full warm, blower motor fan speed on high, and one window open approximately 12 mm (1/2 in). This cures the Cooling Coil Coating onto the evaporator core surface.
10. While the engine is running, rinse the applicator tool with warm water to prolong the life of the tool. Be sure to spray warm water through the nozzle to rinse out any residual Cooling Coil Coating still in the capillary pick up tube, otherwise it will dry and clog the applicator tool. Also remove the small green valve from the bottle cap and rinse it thoroughly while rolling it between two fingers and then reinstall it. If this valve is clogged , the Cooling Coil Coating will not flow through the applicator tool.
11. Shut off the engine and enable the compressor again.
12. Verify proper HVAC system operation.
13. Remove the protective cover from inside the vehicle.
14. Remove the drain pan from underneath the vehicle.
15. Reinstall the cabin air filter if necessary.





Parts Information

Important
The Cooling Coil Coating listed below is the only GM approved product for use under warranty as an evaporator core disinfectant and for the long term control of evaporator core microbial growth.



Originally Posted by Chevtech
Sure you can, but I am hurt, LOL. :

The afterblow mode can be enabled using the scan tool. The afterblow mode allows the blower motor to operate after the engine has been turned off. This operation of the blower motor dries the evaporator core, which reduces the amount of microbial growth which can create undesirable odors.

Use the following procedure in order to enable the afterblow mode:

Connect the scan tool.
Turn ON the ignition, with the engine OFF.
Select HVAC Module.
Select HVAC Systems Automatic.
Select Special Functions.
Select HVAC.
Select Afterblow Option.
Select ENTER to enable the afterblow.
When done, use the soft key to save changes.

KenHorse

autoxnut

I periodically take out the cabin air filter, vacuum it carefully, blow compressed air through it, and then spray both sides with Lysol. This seems to keep the problem under control for me.

cor28vettes

Good detailed post by 08vycpe

This condition (mold) can also occur at the A-coil of your home.

DarkFox1

thanks for the tsb.

What would a dealer charge ballpark to do this?

Doesn't sound like something I wanna do

I never like to work on my DD.. its always the weekend cars that I'm bold enough to wrench on.

cmonkey713

Cheap and effective fix. But "Lysol" I always use Frebreze in mine, smells much better.

CroOrange

A bit OT, what do you use to desinfect your home A/C? Mine smells a bit too much for my taste.

a++ Cedric

cor28vettes

Would not hurt to spray GM P/N 12377951 (mentioned in post #10 above) when coil is dry esp the tubing ends. Then get some UV lights installed by A/C guys. More on OT http://forums.corvetteforum.com/show....php?t=2409900






Just got a List price on that GM aerosol spray...$72.74 ouch! One may be able to get a better price from a forum dlr

0Mike Yeager@Eastcoast Performance

Thanks guys, I will try some of these ideas and let you know how it works out...

0Mike Yeager@Eastcoast Performance

any other ideas..

Grzldvt1

See if you can rent an Ozone Generator that puts out 2000mgh or more.
Set it in teh console on a towel and let it run it for about an hour, with the vents open, windows closed. Then put the HVAC on Recirculate, and run the fan full blast for about 10 -15 minutes or more, the longer the better. Turn everything off, let the car air out for at least five minutes with the fan running and the HVAC set to Outside, close it up and see what it smells like.
The ozone laden air will kill the bacteria and remove the aroma. Sometime you have to repeat the process depending on the aroma and the Ozone Generator.
The worst car I have had in my detailing shop took 16 hours to finally get rid if it, but so what, it wasn't like I had to really do anything. The Ozone generator did all the work.