[accel]

So some time ago I noticed some pretty bad smell coming out of vents which later on proved to be evaporator bacteria\mold buildup. But since I never had this issue before with either of my previous cars, it got (much) worse before I decided to do anything.

If you google on e90 and ac smell, you'll find a bunch of topics which eventually suggest one of the following:

1) Pay dealer to do AC system cleaning
2) Pay indy shop to do the same
3) Check drain hose for clogging
4) Replace cabin filter
5) Use spray <spray> to spray in the vent system intake (under the hood, after cabin filter removal)
6) Use foaming spray <spray with plastic hose> to inject foam into the system from the bottom of the car through the drain hose
7) Spray (6) through vents from the inside the cabin
8) Use lysol instead of spray in case of (5)
9) Disassemble the dashboard, extract the evaporator and do

I tried all things except 1, 2 and 9. I tried every spray / foam available through Amazon/Ebay for 5-8. I tried lots of lysol spray.

All sprays provided only temporary solution. I guess they just masked the smell for several weeks. Instead I had to inhale chemicals included in respective version of the spray. Actually, I think the spray might help if you are proactive and spray immediately after you notice initial weak symptoms.

So, here's what I did today (yes, just today, so the smell might return), but at least I had complete understanding of what I was doing, and I believe, if I repeat the process several times, it will, probably solve the issue, and, it was actually relatively easy to do.

I was able to gain access to the evaporator from inside the cabin. I could even touch it with my fingers, and my fingertips' smell left no doubt as to what's causing the smell.

I sprayed the evaporator with 1-2 gallons of cleaners, which all drained, which supposedly provided enough flow to get things out of evaporator.

I'll explain the process in the next several posts, so be patient.

P.S. Off course, as usual, - if you do it, you do everything at your own risk....

[accel]

First step, follow the "BMW Blower Motor Final Stage Replacement" guide from Pelican Parts to remove the blower motor (Very easy, ~ 10 minutes of work):

http://www.pelicanparts.com/BMW/tech..._Replacing.htm

One clarification - I did not need to remove the vent hose they mentioned. It will be easier to access the evaporator if you remove the hose, but not by much.

Again, the goal is - remove the blower to get access to the hose that leads to the evaporator.

[accel]

Attached it the view at the ac \ vent system of e90 from the TOP.

The brown object on the right (1) is recirculation lid that you can also see from under the hood after cabin filter is removed. The blower is right under the lid (the blower is not in the picture). Once we remove it, we can get access to the hose (2) which goes from the blower to the evaporator. All the work can be done from the inside, passenger seat foot-well area.

This photo gives you idea on what you'll be doing. This whole component is covered by dash board / center console.

Through the hose (2) I was able to reach the evaporator (by inserting my hand in it, just be careful and don't get stuck ), but, obviously, the access is limited, so I could only touch it.

You'll be working in the passenger's footwell. You'll be almost under the brown lid. The evaporator will be inside the center console, where the hose (2) will give you some access.

[accel]

Things I bought:
1) Garden Sprayer.

You can buy any sprayer or reuse the one you already have. I bought 1/2 gallon from the Ace hardware. If you buy - buy the smallest one you can. The space will be limited. Also, buy the one with flexible sprayer hose. You, most likely will need to bend it in different directions as you spray in order to clean as much evaporator surface as possible.

2) Some detergents

I bought lysol and pine sol. Lysol at the picture actually doesn't have nice smell... But I used is since I bought it. I also thought - if I don't like it, bacteria shouln't like it either. I used lysol first, and pine sol next. Still lysol smell remains. So if I did it again, I'd use one more bottle of pine sol after the lysol, or skipped lisol completely. You should, probably, use whatever cleaners you preffer.

Not in the pictures, but I used gloves and protective glasses. Do this outside or in well ventilated area.

[accel]

The hose that goes to the evaporator is behind the glove box, closer to the console, precisely where the blower motor used to be. At the picture you see sprayer's hose inserted in the position ready to spray.

Use whatever concentration and total amount you like (water + cleaner) and pressurize the sprayer. I used hot water in a hope for better effect. Lysol I used was of higher concentration than pine sol. Both build some foam as result of spraying.

I was afraid this would produce lots of water on the inside, but it only made mess outside the car, and you can reduce that by putting some catch can under the car.

Place the sprayer in the foot-well. Put some towel inside the foot-well just in case. Make yourself comfortable, research the hose leading to the evaporator as much as you feel necessary to clearly understand the direction and depth of spraying. Insert sprayer's hose in the direction of the center console.

Start spraying just enough to verify the drain hose of the evaporator is not clogged. I did that before, so I had some confidence that the liquid will drain. Still does not hurt to check - look under the car - you should see liquid under the car. If you do not, I wouldn't continue as there's high risk of flooding the inside of the car.

I had zero liquid inside the cabin, not even a drop - so all the liquid should drain under the car.

[accel]

From this point on, - just refill and spray in different direction/depth. I let it stay and soak for 5-10 minutes between spraying to let cleaners work on bacteria.

It took ~10 minutes to remove the blower and 10 minutes to install it back. The spraying itself took 1.5-2 hours, just because I wanted cleaners to be in contact with the evaporator for more time.

As a result there was a lot of liquid under the car. Lots of cleaner smell.

I suggest you do it outside or at least put some container under the car to catch water. My car has sport package and is pretty low, so I couldn't find anything suitable to slide in, but for the next time I will buy some kitchen oven pan.

I had to water the garage afterwards and still there is still a lot of lysol smell. I've mentioned - the smell is not pleasant, so either use more pine sol after the lysol, or skip lysol completely.

By the time I started using pine sol I inspected the water under the car and noticed a lot of white substance and particles in it. Could be deposits of aerosol sprays I used before, or who knows what it was. At the second picture you can see white areas at the floor where cleaners drained.

Check if you have any leaks inside the car as you spray. If you notice something - I wouldn't continue as you can cause some shortage. In my case everything was dry inside.

After I used both bottles of cleaners I assembled the blower and the panel back in the reverse order. That was easy.

Started the car - everything worked - ventilation system, radio and all other systems. I was a little scared to spray this much water in the car, but looks like evaporator case is pretty isolated, which is as it should be as there's lots of moisture there during operation.

So I started the car and drove it for some time with fan and heater on. No smell of bacteria and lysol +pine sol smell is much better and natural that of those chemical aerosol sprays I used before.

So far so good but I will do this again in a little while just in case. This whole process isn't very difficult and I'd rather repeat it pro-actively than smell bacteria again.

That's it.

[accel]

Some more photos - first picture - view from the bottom - I was putting the towel inside the hose in between sprays, just in case, so that liquid doesn't come back inside the foot-well.

Second picture - view at that same towel from the top, from under the hood, with cabin filter removed. Potentially it is possible to spray from here, but your sprayer's hose should be long enough and have specific shape.

[accel]

And two final pictures:

- Blower motor

- The panel that yo remove in order to remove the blower. As you can see, I used a lot of chemicals before - sprayed in the intake, they carried enough moisture through the system to leave oily\wet spots. But they barely get anything out of the system unlike the approach in this DIY.

[maomaox]

Great. This is super useful. Going to try this someday. Btw did the smell ever come back?

[Agentphish]

Originally Posted by accel

I could even touch it with my fingers, and my fingertips' smell left no doubt as to what's causing the smell.

out of context, this made me lol.

[JeezuzFr3ak]

Has anyone else used this process successfully? I had no issues since Fall 2008 and then suddenly the air from the vents started smelling bad during the Fall of 2014, for no apparent reason.

Like the original poster, I have tried everything else (even Ozone treatment for several hours at the dealer), and nothing has worked.

If this doesn't work, then the evaporator needs to be removed/accessed and cleaned directly or replaced. This is bad, but I suppose it would still be cheaper than buying a new car.

Cheers

[Wilt]

OP, I am curious to hear if your 'foaming spray' efforts included the use of 1Z Einszett Klima-Cleaner, as I have read some positive results posted by a number of users.

[maomaox]

Originally Posted by 09335xibwm

Has anyone else used this process successfully? I had no issues since Fall 2008 and then suddenly the air from the vents started smelling bad during the Fall of 2014, for no apparent reason.

Like the original poster, I have tried everything else (even Ozone treatment for several hours at the dealer), and nothing has worked.

If this doesn't work, then the evaporator needs to be removed/accessed and cleaned directly or replaced. This is bad, but I suppose it would still be cheaper than buying a new car.

Cheers

I just did this a few days ago w/ 1:10 dilution of Pine-Sol and so far it seems to have cured the problem. Besides what the OP used, I also got a endoscope tube camera (http://www.ebay.com/itm/251634553929) and attached it to the sprayer head so that I could actually see the evaporator and where I'm spraying. Worked flawlessly.

[asus389]

Thanks for this post. Now does your car smell like pine-sol all the time? :-)

[mike-y]

tip for keeping the smell away now that you've finally gotten rid of it:

If you use your AC a lot, don't use the recirculate setting all the time, and be sure to turn off the compressor and run the fan for a few minutes before turning the car off. I run the fan a lot (no AC) and almost never use recirc when I use the AC. I run the fan without the AC on for a bit before getting to my destination, and have never had the musty smell in any of my cars.

Going on 7 years with my E90 and it's smell-free

[accel]

Originally Posted by Wilt

OP, I am curious to hear if your 'foaming spray' efforts included the use of 1Z Einszett Klima-Cleaner, as I have read some positive results posted by a number of users.

Yes, they did. But I think the issue is not the spray itself. You can't make the spray cover/penetrate the whole evaporator if you inject in from the cabin or the bottom of the car.

[accel]

Originally Posted by asus389

Thanks for this post. Now does your car smell like pine-sol all the time? :-)

The smell goes away after some time, like a week or two.

[accel]

Originally Posted by maomaox

Great. This is super useful. Going to try this someday. Btw did the smell ever come back?

I have to tell you that I did this procedure several times, - just because it's simple and the smell really drove me nuts for long time. After the source of smell was gone, I sprayed some vent spray in vents, just in case.

And so far it's good.

[mauolaidom]

This is super useful. Going to try this someday.

[Karbon]

Nice DIY.

On another note I can confirm that using recirculate all the time can cause build up of mold / bacteria quickly, especially in hotter climate areas.

I had a slight smell when running my AC and the dealer was kind enough to clean mine out for free under warranty, but the SA told me to avoid using the recirculate function when possible.

He also said turning the AC off and running the fan on high for a while helps dry it out to prevent build up.

[mp-E46]

I bought a BG Frigi Clean kit and will be trying it out by spraying the stuff from the Cabin filter area. Cleaned e46 and lot of gunk came out.

[lug]

Great DIY, and I'm sure a lot of people will find this very helpful.

I don't have any funky smells yet, but has anybody who does tried cranking up the heat all the way for 30 minutes and tried roasting the SOBs near the evaporator (with the windows down so you don't roast too)? I'm guessing if the smell isn't too bad yet, and you give a couple doses of this in addition to turning the compressor off the last mile or so of your commute, you could eliminate the problem before it gets too bad.