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Title: W221 S600 - Severe AC Odor returns immediately after Evap Foam & Vent Cleaners
Hello everyone,
I'm dealing with a severely bad AC odor in my W221 S600 and I've hit a wall.
Here is what I have done so far:
Replaced the cabin air filters.
Injected Liqui Moly Air Conditioning System Cleaner (250ml foam) directly toward the evaporator through the cabin filter housing.
Sprayed Mr. McKenic Air Con Cleaner into all the AC outlet vents.
Ran the heater on high afterward to completely dry out the system.
The result? The smell completely disappeared for a few days, but now it is back and just as bad as before.
Since the chemical treatment only worked temporarily, I suspect I have a physical drainage issue where condensation is pooling and breeding new bacteria.
Has anyone dealt with this specific stubborn issue on the W221? Where exactly are the AC condensate drain tubes located on the V12, and how do you clear them? Could this be the windshield cowl drains pooling water near the fresh air intake?
Any diagrams or advice would be greatly appreciated. Thanks!
If you haven't cleaned out the scuttle by the cabin intake, definitely do this. It should be a service item, easy enough to do but often overlooked. You may even find the cause of the smell.
Also, once you've done it, fit new cabin filters. Don't cheap out though, buy the correct, genuine charcoal ones.
If dead animal you will need find the expired rodent and remove it from wherever it joined the rainbow bridge club.
Sweaty socks? Where the A/C cleaner treatments fail Ozone will get it done. Rent an ozone generator. Let it run inside the car with all windows closed up, the car on a battery maintainer that will keep it alive as you run the blower motor on recirculate. It may take a few days but is effective.
OP it seems they have dropped in price significantly. A quick search online has many to choose from for up to $300.00. Get one that runs on 110V.
It goes on floor at right front. Let ‘er rip. Be sure the car is on a burly battery maintainer as the blower motor runs on recirculate.
Since you say the smell went away after your cleaning process but came back after a few days i would say you are on the right track. Maybe it wasnt cleaned enough. How did you inject the cleaning product, it shows using an old cabin air filter and making a hole in the cover.
There is info on odors in the hvac. Mentions following strict procedures. It goes on to recommend some type of ozone cleaning.
The drain lines are easy to locate, should be behind the carpet/trim in the foot wells.
Have you confirmed your car is performing the evap drying on its own after shutting the car off?
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Title: W221 S600 - Severe AC Odor returns immediately after Evap Foam & Vent Cleaners
