E39 stinky a/c ...

"drd" wrote

There is a drain; don't know where it is on an E39.

Be sure to turn off the a/c a few minutes before parking the car to help dry the evaporator to help alleviate this. If possible, manually select exterior air. It seems that BMW programmed the a/c system to always select re-circulation mode until the interior air is at the desired temp. This really retains humidity in the cabin and ventilation system.

FloydR

I think you might have that last part backwards. Recirculation really should reduce the cabin humidity quicker than that obtained when pulling in outside air, in which case the expansion coil would also more likely be drier in recirc mode than fresh-air mode.

But you were spot-on with the advise to dry out the expansion coil prior to a lengthy parking time. That will go a long way to minimizing A/C funk.

fwiw, it is not uncommon for more intelligent HVAC systems to automagically switch to recirc mode until the interior temperature is within, for example, ten degrees F of the desired/set temperature, at which point they will open the fresh air intake - unless the Recirc mode is forced via console button. Don't know if that applies to the E39 or not, but a little experimentation would go a long way to understanding how that system works...

/daytripper '00 s4 6spd

If the drain is plugged, all the moisture stays in the cabin/system. If it's not plugged, you're correct.

FloydR

Did you switch to re-circ and spray into the cabin air intake?

Switch off the AC a mile or so before you stop, go to fresh air intake and run the fans on max.

I find Febreeze works well to get rid of the smell and is much cheaper than the custom stuff.

"Dave Plowman (News)" wrote

Where exactly are you supposed to spray it? Remove the cabin air filter and spray it into those holes?

Pete

"drd" wrote

It certainly helps.

Easiest thing is to run the a/c in the drive, and look for a puddle. Of course, if there isn't a puddle it's blocked... The drain is a 3/8" tube of flexible plastic.

FloydR

What really amazes me is that BMW goes to a significant effort to get the sounds of the car just right.

Yet BMW seems to care little or not at all regarding the smells of the car. The ubiquitous a/c smell, the crayons smell in the trunk from the sound dampening insulation, etc.

Don't the people in BMW marketing and engineering have noses, or do they have only ears?

Actually I recall reading some long diatribes about smell from BMW (probably the marketing dweebs). But, they are human afterall, and that means that Murphy's Law applies.

PS - all cars that I am aware of have the same stinky-AC problem, especially if you get in the (bad) habit of shutting the car down with condensate on the evaporator coils.

I think maybe BMW employees don't care as they expect you to get a new car every couple of years. Its my understanding that most Germans, in general, don't keep cars for more than a few years. So, if you're a BMW employee and you get a new car ever 2 or 3 years, at I imagine a very good discount, they'll probably don't own the cars long enough to ask "what smell?"

I've been lucky in that I've never had any odor problem with my '99 E46. And my Z4 is just losing it's lovely "new car" leather smell after 4 1/2 years and 40,000 miles. Perhaps I'm the exception that proves the rule...

Tom K.

Smelly AC ain't unique to BMW.

You mean "silence"? When I drove an E90 I was really turned-off by the inability to hear the engine...

Neither have I, with my '00.

I always make sure to turn-off the AC a few minutes before shut-down.

Agreed, funky A/C isn't unique to BMW.

The Crayola smell in the boot - *that* I'm pretty sure is unique to BMW ;-)

/daytripper '00 s4 6spd - no funk, no Crayons

The BMW (E46) is the first car where I have experienced the a/c smell. I've had cars with a/c since the mid-70's (Plymouths, Mazdas).

There are two smells from the a/c: the musty one caused by stuff growing because of poor drainage design, and then there is a background smell whnever the snowflake button is turned off.

So far I have not experienced the former smell.

The latter smell, however, has been there since day one. There was no water condensing because I picked up the car on a cold, dry December day.

I really think that BMW is not as concerned about the ongoing and long-term smells emanating from the aging materials used in the car. Another person on this thread mentioned some marketing stuff about the smells. I remember seeing that in the BMW magazine, but that was more just the new car smell, not ongoing degassing of aging materials.

I really don't like to rant on this, but the crayon smell in my E46 is just awful.

That's a good point. Around here, Audi's (can I say that here?) have the reputation of being designed for leasing (i.e., a 3 or 4 year ownership cycle).

Maybe the same applies to BMWs also.

The engine in my E46 has a nice ~growl~ to it. I can definitely hear it.

Given that leasing is almost entirely a US thing, why would a German car maker design for this?

Beats me. I was just repeating the reputation that audi's have.