How To: A/C Mildew Smell Removal
#1
06-27-2012, 07:34 PM
Join Date: Apr 2011
Location: Seattle
Posts: 6,074
How To: A/C Mildew Smell Removal
Have you ever turned on the air conditioning in your car after not using it for a while and noticed a musty, mildew smell coming from the vents? Chances are you have fungus growth on the evaporator and/or the inside of the evaporator housing. Dealerships and shops will charge you a pretty penny to eliminate the odor, but you can do it yourself for a lot less money. Most major auto part stores sell (or can order) an Evaporator Odor Eliminator Kit. The one I purchased is the A/C Pro part #OE-1 made by Interdynamics. The cost was $12.50 including tax.
There are two steps in eliminating the the offensive odor:
Step 1: Make Sure The Drain Is Clean
A drain tube is built into the bottom of the evaporator housing and exits through the firewall into the engine compartment. Sometimes it can become plugged and allows condensation to accumulate in the evaporator housing. On the 2000-05 Monte Carlo the drain tube is located on the firewall just off center towards the passenger side of the vehicle. I found that the easiest way to access it is to remove the radiator overflow tank. If your vehicle is equipped with a strut tower brace you will need to remove the 13mm retaining nuts on both towers that secure the brace so you can remove it and gain clearance for removal of the overflow tank. Then remove the 2 10mm speed nuts that secure the overflow tank to the inner fenderwell, pull straight up to release it from the catch on the bottom of it and sit it off to the side out of the way. Look at the firewall in the vicinity behind the power steering pump and you will see a rubber tube pointing downward. This is the drain tube for the evaporator. Twist and pull the rubber tube off of the metal drain pipe. If it was plugged up water will flow out of the metal tube. Inspect the rubber tube and clean any blockage from it as needed.
Step 2: Cleaning The Evaporator & Housing
Before cleaning the evaporator and housing you want to make sure there is no debris in the metal drain tube. What you use to clean it will depend on what you have available, but a plastic wire tie, drill bit or pipe cleaner will all do the job. The main idea is you want to slide it in and out of the metal pipe to break up any debris that might be obstructing flow and preventing condensation from draining out of the housing. Once you are sure the drain pipe is clear, take the hose provided in the odor eliminator kit and slide it into the drain pipe as far as it will go. Shake the can of odor eliminator then attach the other end of the hose to the can. Depress the button and fill the evaporator housing with the cleaning foam. Keep the button depressed until you have emptied the entire contents of the can or see foam begin to backflow from the drain pipe. Remove the hose from the drain pipe. Allow the foam to clean the evaporator and the housing. As the foam cleans it will turn to a liquid and drain from the metal tube. This will take about 10 to 15 minutes. Once the cleaner has stopped draining start the vehicle (make sure the overflow tank is not resting on any pullies or the serpentine belt), turn on the A/C and set the fan on the low position. Allow the A/C to run on low for about 5 minutes then turn the vehicle off.
Push the rubber tube back onto the end of the metal pipe making sure it points downward. Reinstall the overflow tank and the strut tower brace.
You should now be able to enjoy crisp, fresh smelling A/C in your car.
There are two steps in eliminating the the offensive odor:
Step 1: Make Sure The Drain Is Clean
A drain tube is built into the bottom of the evaporator housing and exits through the firewall into the engine compartment. Sometimes it can become plugged and allows condensation to accumulate in the evaporator housing. On the 2000-05 Monte Carlo the drain tube is located on the firewall just off center towards the passenger side of the vehicle. I found that the easiest way to access it is to remove the radiator overflow tank. If your vehicle is equipped with a strut tower brace you will need to remove the 13mm retaining nuts on both towers that secure the brace so you can remove it and gain clearance for removal of the overflow tank. Then remove the 2 10mm speed nuts that secure the overflow tank to the inner fenderwell, pull straight up to release it from the catch on the bottom of it and sit it off to the side out of the way. Look at the firewall in the vicinity behind the power steering pump and you will see a rubber tube pointing downward. This is the drain tube for the evaporator. Twist and pull the rubber tube off of the metal drain pipe. If it was plugged up water will flow out of the metal tube. Inspect the rubber tube and clean any blockage from it as needed.
Step 2: Cleaning The Evaporator & Housing
Before cleaning the evaporator and housing you want to make sure there is no debris in the metal drain tube. What you use to clean it will depend on what you have available, but a plastic wire tie, drill bit or pipe cleaner will all do the job. The main idea is you want to slide it in and out of the metal pipe to break up any debris that might be obstructing flow and preventing condensation from draining out of the housing. Once you are sure the drain pipe is clear, take the hose provided in the odor eliminator kit and slide it into the drain pipe as far as it will go. Shake the can of odor eliminator then attach the other end of the hose to the can. Depress the button and fill the evaporator housing with the cleaning foam. Keep the button depressed until you have emptied the entire contents of the can or see foam begin to backflow from the drain pipe. Remove the hose from the drain pipe. Allow the foam to clean the evaporator and the housing. As the foam cleans it will turn to a liquid and drain from the metal tube. This will take about 10 to 15 minutes. Once the cleaner has stopped draining start the vehicle (make sure the overflow tank is not resting on any pullies or the serpentine belt), turn on the A/C and set the fan on the low position. Allow the A/C to run on low for about 5 minutes then turn the vehicle off.
Push the rubber tube back onto the end of the metal pipe making sure it points downward. Reinstall the overflow tank and the strut tower brace.
You should now be able to enjoy crisp, fresh smelling A/C in your car.
#2
10-06-2012, 11:44 AM
Great write up, thanks!
Is that the same drain that would be clogged if water started leaking into the car? ie the condensation you see dripping onto the ground?
Reason I ask is, wife's 2003 leaked one time into the car. Since then, the AC hasn't blown cold.
I took that cap off, doesn't appear to be clogged. Hard to get under the car to look for another drain.
Trying to prep to sell/trade in the car. Don't want to put a lot of money into it.
Would like to find the other drain if it exists.
Again, thanks! Gonna do this anyway!
Brad
Is that the same drain that would be clogged if water started leaking into the car? ie the condensation you see dripping onto the ground?
Reason I ask is, wife's 2003 leaked one time into the car. Since then, the AC hasn't blown cold.
I took that cap off, doesn't appear to be clogged. Hard to get under the car to look for another drain.
Trying to prep to sell/trade in the car. Don't want to put a lot of money into it.
Would like to find the other drain if it exists.
Again, thanks! Gonna do this anyway!
Brad
#4
10-06-2012, 02:53 PM
How didn't I see this sooner?!? 
Excellent write up. I need to do this badly! I've been noticing an odd smell while using the a/c all summer. My quick fix was to not use it and roll the windows down
Glad to hear there's an actual solution to it
Excellent write up. I need to do this badly! I've been noticing an odd smell while using the a/c all summer. My quick fix was to not use it and roll the windows down
Glad to hear there's an actual solution to it
