Air Conditioner Smell - PeachParts Mercedes-Benz Forum

lbensky · #1 07-20-2002, 04:26 PM

A bad smell started coming from my air conditioner and soon after the 'check engine' light came on. I brought the car to the local MB dealer and they said the light was indicating the purge valve was bad. I had them replace the purge valve but the stink remains from the air conditioner. Any clues or suggestions? I am holding my breath...

LB

Maddog · #2 07-20-2002, 07:14 PM

Because evaporators tend to get wet from condensation, bacteria will grow on them. The only way to prevent this is to run turn the air con off a few minutes before you shut the car down and run outside air through the evaporator. To get rid of the smell, Turn your fan to circulate the air in the car....no A/C, get some lysol disinfectant..UNSCENTED!!!! and spray it into the air induction outside where the air is pulled in the car. This should kill all of the bacteria.

#3 07-20-2002, 07:37 PM

lbensky, Is the car you're talking about gas or diesel? The purge valve is probably fuel evap system related. Is the smell fuel or does it have a musty odor. Is this car 1996 or newer?

Holson Adi · #4 07-20-2002, 07:57 PM

Quote:

Originally posted by Maddog
Because evaporators tend to get wet from condensation, bacteria will grow on them. The only way to prevent this is to run turn the air con off a few minutes before you shut the car down and run outside air through the evaporator. To get rid of the smell, Turn your fan to circulate the air in the car....no A/C, get some lysol disinfectant..UNSCENTED!!!! and spray it into the air induction outside where the air is pulled in the car. This should kill all of the bacteria.

That sounds like a good idea. Where is the fresh air vent?
Are they the two grilles behind the hood on the body?

lbensky · #5 07-20-2002, 08:19 PM

Th vehicle is a 1994 E320 with 82k. I will try the Lysol disenfectant but I might get the summer fresh scent since I like smelly (good) stuff. Thanks for the tip...

Maddog · #6 07-20-2002, 09:13 PM

I don't know your car specifically but if you have those vents between your windshield and your hood...those are probably them. Just turn the fan on high inside the car and see if you can either hear or feel the air going in. But if you have those vents, thats where it is.

#7 07-21-2002, 09:36 AM

There is a standard spray that is used by air conditioner people to get rid of the smell. I have never used it, so for all I know, it might be lysol in a differently marked can.

I saw some of this stuff on the shelf next to the freon at Pep Boys.

Good luck,

Arthur Dalton · #8 07-21-2002, 09:48 AM

The lysol trick will kill what is there, but it will return. The solution is to clean out the 2 drains from under the car. Rubber flaps on each side
of/above the trans.
The evaporator water is staying in the car.

It is also advisable to replace the air intake filters under the
hood [ there are 2 on your car]. Blocked filters don't let enough
air into the housing to evaporate the moisture when the car has been turned off and left standing...

JCE · #9 07-21-2002, 10:05 AM

Arthur:

I have done the lysol/drain clean tricks before on my Acura, and it worked pretty well. But this is my first car with an air intake dust/odor filter. If/when I develop the same problem on this car, do you think the filters will interfere with the Lysol spray? Would it be worthwile to remove the filters, spray with Lysol, THEN add new filters? Thanks for any insight.

Arthur Dalton · #10 07-21-2002, 10:59 AM

John
Absolutely.

Unfortunately, on the car in question. they are a B---h to change...

stevebfl · #11 07-21-2002, 11:26 AM

I can't stand odors, probably comes from an alergenic, asthmatic, youth.

No little pine trees for me. Florida has to be about as bad as it gets for mildew growth on evaporators and in the last two years I have had it on both my wifes ML and my 540i. Luckily I hired a tech from Toyota about two years ago and he turned me on to the best stuff. It is hooked to the drain under the car and a whole aerosole can is exhausted. It creats a foam that permeats the entire evaporator case. After about 20 minutes it condenses back to a liquid that flows back out the drains. The kit also comes with a spray to put into the air intake but it smells so I didn't use it.

After first doing it to my wifes ML, I was really worried because the car smelled of amonia when I drove it home. I forgot about it for a week and then asked her if it still smelled of amonia. She said she never smelled it. I have driven the car numerous times since and absolutely no smells other than the new car smell.

We have used it in the shop a number of times now and I have one word of warning. Most older MBs have A/C drain tubes that are made of a foam rubber tube with 7/16 in wall thickness covered with a thin water tight film. The foam often is in terrible shape. The method of introduction of the product requires a tight seal to the bottom of the evaporator case. On 300Es that we have done we have had to replace the drain tubes after pulling the wimpy ones and hooking the product right to the evap hard tubes (inside the car).

#12 07-30-2002, 02:42 PM

similar problem. Dealer sprayed something in to kill bacteria - but it smelled worse than the bacteria (like the little smelly tablets they put in toilets). When that finally stopped smelling, the dealer suggested spraying lysol in the intakes. or you can use a product called "Refrigefresh". I went with the lysol as you can get it in any smell you want. Best I found was the lysol smell that is supposed to smell like freshly ironed clothes (rather than pinetrees, etc.). It worked great. Sprayed in a few times over a day or so and after that smell cleared out the original bacteria smell is gone.