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Cleaning the AC condenser

18K views 12 replies 6 participants last post by  davekra 
#1 ·
I've had a mild musty smell when you turn on and off the AC. I usually shut off the AC a few miles before turning off the car so I'm kinda surprised it's started to smell.

Not happy with just blindly spraying stuff into the fan or flooding the interior vents with something that could stain the interior I decided to remove the entire blower unit.

There's some cables and cable clips that need to be moved. Electrical connections to the fan and recirculate vent. The big connectors to the ECM don't need to be removed, but the bracket that holds it need to be unbolted.

The pics attached have the locations for screws circled in red. The arrow is a clip that needs to be released. You can see in one pic that there's a hook like thing on the top of the duct where it connected to the box with the AC core still in the car.
It will take a little forcing and tugging to get the blower out but it wasn't hard.

One of the pics shows the condenser. It doesn't look too dirty. It's angled such that if debris does get in there it won't lay on top of the coil. I'm going to use a garden sprayer to clean it. Does anyone have any advice on what chemicals to use?
I'm concerned that some of the foaming cleaners are actually dissolving some of the aluminium. There's a cleaner from Diversitech called Triple-D that looks promising.
 
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#4 ·
I'm kinda looking for something local. Like from Graingers (going to stop by them tomorrow)
The local auto stores don't have anything but air fresheners. I'm looking for disinfectant.

The filters been replaces a few times in it's 38k. There's no smell in the blower. It's all coming from the condenser. The duct before the filter had some normal dirt on the walls but after the filter it's pretty clean.
 
#6 ·
#8 ·
See what you mean about the video. the stuff I suggested does not seem that harsh you could check this out it says its non acidic.
Coil Cleaner, 16 Oz, Clear - AC & Ref Cleaners and Scale Removers - AC Refrigeration - 4PDA8 : Grainger Industrial Supply

also if your coil is not real dirty maybe a disinfectant spray like this would eliminate the odor without damaging the coil.

Liquid Disinfectant, 32 oz Spray Bottle - AC & Ref Cleaners and Scale Removers - AC Refrigeration - 2YJ72 : Grainger Industrial Supply
 
#9 ·
Thanks again. A disinfectant sounds about right.

I've found there are acidic or alkali cleaners. Both, if the concentrations are right, will dissolve AL.
Looking at the MSDS for the Evapfoam it includes ammonia and caustic soda and some other stuff, but the concentration of the soda is only .08%. Some have concentrations up to 30%! The acidic ones seem to have phosphoric or hydrofluoric acid.
Concentration and time in contact have a lot to do with how much AL is dissolved.

The Foamy Clean only has dipropylene glycol monomethyl ether which is almost a neutral PH. That one sounds like a winner. Do a little overkill and use Foamy Clean then rinse it with the disinfectant?

I'm off to visit Graingers right now. I'll see what they have in stock but probably end up ordering something from them.
 
#10 ·
Good luck, If you use one that needs to be rinsed I would use a spray bottle of clean water so you dont need to drag a hose into the car. Let us know how it turned out. RR
 
#11 ·
my parents 2009 was allowing condensation from the A/C evaporator to spill over into the cabin rather than drain through the drain tube outside under the car. the entire carpeting was getting drenched and pooling up in the passengers side footwell. watching it i couldn't see why but that it wasn't going through the drain tube obviously, though everything appeared attached properly.

i tried cleaning tube while on the car but i wasn't helping.

so i pulled the drain tube out, cleaned it out, and reinstalled it and it's been fine ever since. i did not notice any debris at all (i was looking for it) or any signs of issues. i suppose it was kinked, debris, a bug harboring something...etc, but that simple process fixed it entirely.

theirs was draining internally but i can easily imagine a scenario where it just partly drains inside or pools up improperly in the tube and is allowed to get locally humidified and cause musty smells because it's not fully draining....might be worth trying what i did?

the only ones i've ever noticed were cabin filter related.

OZONE generators are excellent and neutralize the odors rather than cover it up. and get all up in everything with virtually no work. rent them at local tool rental places (like places that rent mowers, tractors, heavy equipment, etc) or there are online options where you rent for a few days or a week, they ship and you ship it back.
 
#12 ·
When I do this tonight or tomorrow I'm going to check the drain hose. To my knowledge it's draining properly but I'm going to remove it for inspection.
The filter and fan show no signs of problems.

To be honest the smell is just barely there. It's enough that I notice it though. And I don't usually do things the easy way which is why I removed the blower.
I like to be thorough when I do something and do it well.
We'll see what kind of results I get. I can always find a professional if it has less than perfect results. But, then again, I could remove more of the dash to get better access to the cores and try again. It's a fun project none the less.
 
#13 ·
Ok, so it is a qualified success.

I ended up putting a 1/4" hole towards the top of the evaporator housing. I used a soldering iron because they way I figured it, a soldering iron wouldn't accidentally put a hole in anything inside like a drill might.
I didn't take a pic of the hole but the drawing shows about where it goes. You can see the outline of the evaporator on the plastic housing. You can also see a semi-circular bit molded into the housing. The semi-circular part must be a baffle for directing air. In other drawings the drivers side of the housing shows an actuator. I put the hole closer to the evaporator so it wouldn't interfere with the baffle.

I modified a garden sprayer with a piece of brass tube. I crimped and sealed one end and cut half way with a razor saw. You can see in the pics what it is and the kind of spray pattern.
I was able to insert it into the hole and draw it out as I sprayed. I also inserted it into the large port where the blower connected.

Since the thing was pretty clean and I just wanted to eliminate the smell I used a disinfectant like Red suggested. The Easy Foam from Graingers had a sickening sweet smell that didn't seem to go away in the tests I did. I looked at the MSDS for coil cleaners and found the active ingredient was found in most disinfectants. So I got some OdoBan from Home Depot. Diluted it with water and used the sprayer to soak the evaporator. Let it sit for 5minutes and flushed with water.
The result was perfect. No musty smell and no smell of the cleaner.

Lessons learned:
The blower comes out easier than it goes back in. I ended up cutting some of that hook on the top where it connects to the other housing and the screw closest to the firewall wouldn't go back in. I couldn't line up the holes, but the foam around the duct was able to seal it. It's only 1/16-1/8" off but enough not to be able to get the screw stared.

Cleaning the evaporator could probably be done without removing the blower. The hole would still be necessary and you could probably use the hole on the bottom of the blower housing that the blower resistor goes into. I'm not sure if there would be enough room to insert the brass tube so you might have to have something a little flexible like semi-rigid plastic.

Over all a success. I didn't mind removing the blower as it gave me a good idea of where the evaporator was and what was around it.
 
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