A while ago I had noticed the AC in my wife's 08MCS smelled for maybe 30 seconds after starting the car and then the smell went away. It's her car, not mine, and she had never complained so I made a note to check here. 11ty threads said "change the cabin filter" and I thought you know it's been almost a year since I put a new carbon filter in, so I did that and figured the problem went away.

She never complained so I thought all was good, right? Well lately I've been using her car and noticed it still smelled. I did some other research and saw threads about a clogged drain tube, or a moldy evaporator, so I decided to try something new.

AutoZone carries two products, one is meant to be sprayed in the vents in the hopes the spray drips down onto the evaporator (it looks like a tiny can of compressed air), this one is meant to go in from below. P/N is "OE-1", cost was $10.99. The guys might not even know they carry this product, ours had to go look in the back, and judging by the packaging I doubt this is on any shelves out on the store floor.


Inside the box you have a ~redbull sized can and a long hose.


If you've never noticed or looked but didn't find, the drain tube is here.


Ours did not look blocked. I gently pushed a long and thin phillips screwdriver until it wouldn't go anymore. No gush of water. I looked around for something more flexible to see if maybe it was just hitting a bend (if you look on realOEM the part is molded with a slight curve) but I couldn't find anything.


I started to slide the hose up into the drain tube, but it started to catch. I rubbed a little vaseline around the tip and on the clear tubing. This helped a lot. I pushed the hose until it felt like it was far enough up to do it's job. The can said spray for 15 seconds or until foam starts draining out of the tube. It took 18-20 seconds.


Let sit for 10-15 minutes and then start the car and run the AC on low for 5 minutes. I did this and voila, the AC smelled like fresh laundry.


Who knows how long this will last, but after 18-20 seconds the can still felt half full, so if it does come back I can try again. I would imagine this would be more effective if you did want to go in from above as well, since you can snake the tube down where it is needed.

 

You could also have a small leak in the evaporator, coolant has an odd smell. Happened to me once..

 

i already replaced the condenser so that'd be 2 for 2 as far failed cooling system heat exchanger components are concerned. fingers crossed this fixes it.

getting to the evaporator looks like a *****

 

Yes it is. When it happened to me on a previous vehicle, was wicked expensive to fix. The part wasn't too bad, but the labor was a killer..

 

Nice DIY , did you have any discolored liquid come out. Did it get ride of all the smell after a while.

 

nothing gross came out and the AC does smell good still.


if it does come back i will probably try an alternate method. if you open the cabin filter box and take the filter out, it looks like I could snake my arm up into the area where the blower motor resides. I should probably be able to angle the nozzle downward and spray it from the top side.

 

Yea, also check for things that might have made it by the cabin filter, if the cabin filter is not seated well things could get by. I had a leaf once on a change get by as it fell off the filter and into the duct, good thing i looked up and saw it. Rotting debris can cause a stench over time. Used the carbon version to combat any smells.

https://www.northamericanmotoring.co...er-filter.html