I've noticed a slight moisture smell to my HVAC for a while now, I thought at first it was just when it's humid but I'm smelling it all the time now, looking at the Lubegard option and it seems like the best. Fills the Evaporator core box with foam, and then that foam turns into liquid and drains. Anyone have a good experience with this, or should I look at something else?
Evaporator Core Cleaning
- Thread starter Ang
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GON
$150 Site Donor 2025
Here is a video of a technician doing the exact service you are inquiring about. I watched this video over the weekend and found it time well spent.
While i have a Honda, Not a Subaru, It seems subarus cleaning kit is about the same price as Lubegard but with the Refresher, if i can find one without insane shipping i suppose i could use the Subaru one. my only concern with the refresher is adding a scent to the car. i like that my cars don't smell dirty, and don't smell like an air freshener, i don't want to get in the car and smell a cleaner or air freshener. Also a little concerned about if the foam ends up being to much for this specific vehicle and gets into other areas, but i guess i don't have a choice, i need to clean it.
GON
$150 Site Donor 2025
I used to do these services when I worked in a dealership. Never had a bad experience as a result except with my personal vehicle 
. You foam it up through the evaporator drain tube and let it turn to a liquid and drain back out.
My issue was that I guess the foam reacted with my HVAC blend door sealing foam, so the next time I tried to change temperatures my blend door could not move. I rarely change my HVAC temp, I’m more of a leave it completely cold type of guy, so it was awhile before I tried to change temperatures.
The insulating foam actually melted, so the door was stuck full cold. I’ve never seen it happen before this or again but I hesitate to ever use such a product now. I’ll use the spray that you use through the fresh air intake, but I don’t think I’ll ever use the foaming cleaner again.
. You foam it up through the evaporator drain tube and let it turn to a liquid and drain back out. My issue was that I guess the foam reacted with my HVAC blend door sealing foam, so the next time I tried to change temperatures my blend door could not move. I rarely change my HVAC temp, I’m more of a leave it completely cold type of guy, so it was awhile before I tried to change temperatures.
The insulating foam actually melted, so the door was stuck full cold. I’ve never seen it happen before this or again but I hesitate to ever use such a product now. I’ll use the spray that you use through the fresh air intake, but I don’t think I’ll ever use the foaming cleaner again.
What cleaner did you use, and what brand vehicle?I used to do these services when I worked in a dealership. Never had a bad experience as a result except with my personal vehicle
My issue was that I guess the foam reacted with my HVAC blend door sealing foam, so the next time I tried to change temperatures my blend door could not move. I rarely change my HVAC temp, I’m more of a leave it completely cold type of guy, so it was awhile before I tried to change temperatures.
The insulating foam actually melted, so the door was stuck full cold. I’ve never seen it happen before this or again but I hesitate to ever use such a product now. I’ll use the spray that you use through the fresh air intake, but I don’t think I’ll ever use the foaming cleaner again.
I happen to have a replacement foam seal for the air box door, so I could take a piece of of the existing messed up seal and spray some cleaner on it I suppose. The plan though is to not have it flood everything and get into the blend doors, that's what I want to try and avoid. Maybe I can get a camera into that area and see when it fills up so I can stop it.
Hyundai/Kia and Toyota/Subaru both rebranded a Wurth product for their A/C refresher kits
https://www.wurthusa.com/Chemical-P...hfbXZnX5fvHrHiYY8GLSX3a_-1zF6NFXZBvoL01tvOEHn
I use them, and people like them
They disband with A/C stank and leaves a lemon fresh
scent
Costs are up tho, so I got a bulk deal on some Valvoline branded cans of the same principle
Wash the condenser with an appropriate coil cleaned, and a fresh cabin filter to finish the job
https://www.wurthusa.com/Chemical-P...hfbXZnX5fvHrHiYY8GLSX3a_-1zF6NFXZBvoL01tvOEHn
I use them, and people like them
They disband with A/C stank and leaves a lemon fresh
scentCosts are up tho, so I got a bulk deal on some Valvoline branded cans of the same principle
Wash the condenser with an appropriate coil cleaned, and a fresh cabin filter to finish the job
dnewton3
Staff member
These are common and actually, when done properly, are worthwhile.
Of the several examples, The Car Care Nut also has done a video of same process.
I don't believe the product brand matters; it's process sensitive more than anything else. Get the foam all the way up and cover the whole EVAP coil.
Of the several examples, The Car Care Nut also has done a video of same process.
I don't believe the product brand matters; it's process sensitive more than anything else. Get the foam all the way up and cover the whole EVAP coil.
Hyundai/Kia and Toyota/Subaru both rebranded a Wurth product for their A/C refresher kits
https://www.wurthusa.com/Chemical-P...hfbXZnX5fvHrHiYY8GLSX3a_-1zF6NFXZBvoL01tvOEHn
I use them, and people like them
They disband with A/C stank and leaves a lemon fresh
Costs are up tho, so I got a bulk deal on some Valvoline branded cans of the same principle
Wash the condenser with an appropriate coil cleaned, and a fresh cabin filter to finish the job
That's exactly what I don't want, a Scent. I don't want my cars to smell like an air freshener, I want it to be neutral and have no difference inside vs outside. I picked up the Lubegard with a coupon to try.
Different brands could use different chemicals
Unsure the cleaner I used but it was an oem, I worked in a Hyundai Subaru shop although I was Chrysler Jeep, we shared work when needed or when one side was overloaded. If I had to guess it was Subaru branded, I know Chrysler Jeep didn’t have it and I don’t think our Hyundai franchise did either.
I very well could’ve used too much, or maybe I was supposed to foam it with the blend door not at full hot or cold limit.
It was on a 2003 accord.
Good topic / product to alert people to.
That first video (thanks GON) so should've been 5 minutes long. Double and triple spoken phrases....torturous.
+1 on wanting a report on the LubeGard product performance.
The LubeGard product appears to not include a second can, the intake freshener spray.
Could plain old Lysol spray substitute? hmmmm...if the scent of the cleaner doesn't clash with the Lysol.
That first video (thanks GON) so should've been 5 minutes long. Double and triple spoken phrases....torturous.
+1 on wanting a report on the LubeGard product performance.
The LubeGard product appears to not include a second can, the intake freshener spray.
Could plain old Lysol spray substitute? hmmmm...if the scent of the cleaner doesn't clash with the Lysol.
- Joined
- Apr 13, 2025
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This thread caught my interest.
That "smell" is usually rotting material mainly from trees that pass through the intake screens and wind up in the evap housing. Many new cars have filters to prevent that. That rotting smell indicates an acidic condition that is likely corroding your aluminum evaporator core. Cleaning out the evap core periodically is a GREAT thing to give your evap core the longest service life possible.
Just putting this out there but....you would benefit just as much (maybe more) by simply running water up into the core housing and letting it flow back out the drain, flushing the junk out. Of course, you have to be very careful not to overfill the core and just add an inch or two and repeat this several times until the water clears up. The debris usually settles to the bottom. Yeah, you might get a little water leakage inside the car but get some towels and put under the evap housing first. Doing this once a year would prolong the life of the evap core considerably if junk is prone to get in there.
Mold and mildew is a bit different. You might need a chemical to treat and remove that.
Like many here, I've changed a number of evap cores on different vehicles.
Whatever you do, MAKE SURE you use Aluminum FRIENDLY chemicals only.
That "smell" is usually rotting material mainly from trees that pass through the intake screens and wind up in the evap housing. Many new cars have filters to prevent that. That rotting smell indicates an acidic condition that is likely corroding your aluminum evaporator core. Cleaning out the evap core periodically is a GREAT thing to give your evap core the longest service life possible.
Just putting this out there but....you would benefit just as much (maybe more) by simply running water up into the core housing and letting it flow back out the drain, flushing the junk out. Of course, you have to be very careful not to overfill the core and just add an inch or two and repeat this several times until the water clears up. The debris usually settles to the bottom. Yeah, you might get a little water leakage inside the car but get some towels and put under the evap housing first. Doing this once a year would prolong the life of the evap core considerably if junk is prone to get in there.
Mold and mildew is a bit different. You might need a chemical to treat and remove that.
Like many here, I've changed a number of evap cores on different vehicles.
Whatever you do, MAKE SURE you use Aluminum FRIENDLY chemicals only.
Last edited:
dnewton3
Staff member
Meehhhhh ... Yes, and no.
The EVAP coils, and condensing coils, are made of aluminum fins and, often these days, aluminum tubes. Aluminum is very sensitive to certain chemicals, so it's not like a company can use just any willy-nilly cleaner. Below are the SDS lists for the Wurth and LubeGard products.
https://lubegard.com/wp-content/uploads/2024/04/SDS-96030-Kool-It-Evaporator-Heater-Foam-Cleaner.pdf
https://ehs.wuerth.com/ehs4customers/#/search
