govertime

I plan on cleaning the A/C system to rid mildew/mold buildup.

I'm aware of a number of ways to:

• prevent buildup (turn off A/C a few minutes before shutting off engine or using Rest/Recirc after shutting off)
• spray lysol directly in climate intake/windshield cowl and/or vents
• 70% alcohol 30% water in mist bottle doing aforementioned.
• 1Z Clima-Cleaner
• BG Frigi-Clean (Evaporator Foam) & Frigi-Frest (Vent Spray)
• Petro Chemical AC Refresher Kit (trying to track down where to purchase)

The BG Frigi-Clean product requires disassembling the dash and drilling a hole into the evaporator housing to apply the foam.
The 1Z product you insert the included spray hose into the center air vent and hopefully gets close to the evaporator housing.
The Petro Chemical AC Cleaning System apparently connects to the Evaporator drain tube and the foam is applied that way. See this and this.


If I can find the Petro (Amrep) Chemical AC Refresher Kit, I think I'm gonna do that since it seems to be a good balance of ensuring you get into the evaporator housing but still is pretty straightforward and easy to do. Either way I'm going with a foam since it should be longer-lasting, and hopefully have a less intrusive smell than lysol.

Anybody know where and how to access the A/C Evaporator drain?
Any diagrams and/or brief write-ups would be extremely valuable and greatly appreciated!!!

govertime

BTW, seems the Petro Chemical product is also labeled by Amrep Chemicals and sold by various dealerships as a "A/C refresher kit" and contains isopropyl alcohol.

Glyn M Ruck

See pipe at bottom of housing that drains through floor of car. You can check it for blockage from under the car where it drips

Glyn M Ruck

BTW - you can sort of access the evapourator from the Charcoal filter access area next to the blower. If you don't have Charcoal filters - some models have blanks inserted - you can remove these. Unfortunately some later models have this access blanked off. Depends on your car.

govertime

Glyn you're the bees knees!

I suppose the evaporator is '4' in the first diagram.?? Then I guess '3' is the condenser.
I'm a bit hesitant since this diagram shows the flow of cold outside air being heated for the cabin.

I'll see if I can spot where under the car this drain is...hopefully I can get a pic to post.

Mods - This might be handy as a DIY sticky

Glyn M Ruck

4 is the heater radiator/heat exchanger

Glyn M Ruck

RU seeing all three diagrams? I find the forum messes around.

3 is the evapourator in Diag 1 or 230 in Diag 2

1 in Diag 1 is the fresh air filter

Glyn M Ruck

The condenser is mounted up front of the car with the radiator.

Glyn M Ruck

Here is the basic A/C cooling circuit without all the heating & airflow junk to confuse the issue.

cij911

Bump for similar help with a w211....thanks in advance

rpabalan

where do I access evaporator coil so I can use the kilma cleaner?

TexasBenzBandit

Yeah?

ygmn

thru ducts and where AC sucks cabin air when on RECIRC mode. and possible where cabin filter is.

KevinH2000

https://mbworld.org/forums/attachmen...y-a_c-odor.pdf

I used this document to identify the recommended location for drilling into the duct.

I’ve treated the system with several different products, but the smell returns. If you find a product that works permanently please share the information.

ygmn

nothing works permanently since the evaporator will continue to have water condensing on it and dripping out the car.

Once off this wet evap is in a dark warm place which Bacteria loves....

Check your drain hose make sure it is really clear and allows all the water to drain out.

One way to prevent is: before you shut off your car - turn off AC and crank heater to dry evap... PIA to remember to do but keeps evap dry when not in use.

benzw205

hello, did you fix it ? thank you.

Socal Sam

Bumping an old thread... Thanks to @KevinH2000 for helping in my other thread. I have the dash apart for deep cleaning stubborn odor. This gives excellent access to AC blower motor and air inlet duct.



It appears air inlet duct leads straight to evaporator so will be applying foaming and self-rinsing cleaner. Home Depot has this:

https://www.homedepot.com/p/Simple-G...E&gclsrc=aw.ds

Simple Green product is inexpensive (unlike Toyota Refresh Kit) so multiple cans can be used on both evaporator and heater core. Toyota kit has aerosol can top with tube which can be used with Simple Green can.

I previously applied Toyota cleaner through rubber drain tubes that run from blend box to transmission tunnel which helped a lot. I had mistakenly identified these rubber tubes as access to evaporator. These tubes access heater core and bottom of blend box which is where water and mildew can accumulate. Applying cleaner through these tubes successfully removed smell and confirmed there is no blockage. If odor returns, drain tubes will be part of cleaning. On a side note, I think it is possible to rinse evaporator and heater core with distilled water.



Above photo shows passenger side. Still looking for the access hole drill point shown in the Service Bulletin. Mine car is not equipped with carbon cabin filter so white foam block is present. Looking for the alternate drill hole location.

Socal Sam

Spraying foam cleaner does result in cleaner making its way to the drain tube and out of the car. Black vent tube is not water resistant so be ready with a towel for drips.