Automatic air conditioning

ymdd · 08-12-2012, 10:18 PM

Does anyone have this problem when opening the car the A/C starts on its own, now that's not that big of a deal but my problem is with the smell that comes out of the A/C when I start it, I don't know how to explain It to you guys. But the smell goes away after the car gets moving.
Any ideas???

KINetics · 08-12-2012, 11:54 PM

I found it to be quite common with BMWs. It happened with my E46 and this problem appears on many BWM forums. From what I've researched it's basically occurs from the A/C unit being left on when the car is shut off. Since there is a differential in temperature from the HVAC unit and the ambient temperature, condensation forms in the venting system. This condensation sits and allows bacteria to grow within the system. The next time your car turns on and the vent starts to blow, you're smelling the bacteria that was growing. (Have you ever left your clothes in the washer after the spin cycle and not put it in the dryer for a few days, and it smells "sour" after you dry it?...same thing.)

The more often this cycle of condensation, bacteria growth occurs the stronger the smell will happen over the life of your BMW. The service center will swap out your cabin air filter, and it will help just a bit perhaps, but the bacteria is really growing within the vents and nothing short of an entire vent swap will get rid of it.

From what I heard, Mercedes has an option that will turn off the A/C and blow the vents on High after you shut off the car so that this type of thing doesn't happen.

I'm surprised BMW hasn't implemented such a thing.

I resorted to doing this manually by turning off the A/C and putting the vents on high as I pulled into a store parking lot or my own garage with my e89 and there were no issues.

If it's really bad, you can open the hood, take out the cabin air filter, turn your HVAC on high without A/C, and spray lysol down the vent and hope the lysol kills some of the bacteria.

juhap · 08-13-2012, 02:21 AM

I had this issue too, but it disappeared after a while on its own.

ymdd · 08-13-2012, 08:51 AM

Can BMW do something to fix it?

ManiacGT · 08-13-2012, 10:16 AM

Quote:

Originally Posted by ymdd

Can BMW do something to fix it?

Probably..

ymdd · 08-13-2012, 05:16 PM

Has anyone else encountered this ?

fre2bpowerless · 08-13-2012, 08:50 PM

A/c on 'high' temperature for a couple of minutes does the trick for my newer Audi. I do that every few weeks, no such issue on the Z or my F10s

ymdd · 08-13-2012, 09:27 PM

Quote:

Originally Posted by fre2bpowerless

A/c on 'high' temperature for a couple of minutes does the trick for my newer Audi. I do that every few weeks, no such issue on the Z or my F10s

And did this get rid of the smell ?

08-12-2012, 10:18 PM	#1
ymdd Private First Class 17 Rep 107 Posts Drives: not fast enough Join Date: Apr 2012 Location: usa iTrader: (0)	Automatic air conditioning Does anyone have this problem when opening the car the A/C starts on its own, now that's not that big of a deal but my problem is with the smell that comes out of the A/C when I start it, I don't know how to explain It to you guys. But the smell goes away after the car gets moving. Any ideas???
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08-12-2012, 11:54 PM	#2
KINetics Enlisted Member 1 Rep 42 Posts Drives: Z4 sDrive35i Join Date: Aug 2008 Location: Irvine, CA iTrader: (1)	I found it to be quite common with BMWs. It happened with my E46 and this problem appears on many BWM forums. From what I've researched it's basically occurs from the A/C unit being left on when the car is shut off. Since there is a differential in temperature from the HVAC unit and the ambient temperature, condensation forms in the venting system. This condensation sits and allows bacteria to grow within the system. The next time your car turns on and the vent starts to blow, you're smelling the bacteria that was growing. (Have you ever left your clothes in the washer after the spin cycle and not put it in the dryer for a few days, and it smells "sour" after you dry it?...same thing.) The more often this cycle of condensation, bacteria growth occurs the stronger the smell will happen over the life of your BMW. The service center will swap out your cabin air filter, and it will help just a bit perhaps, but the bacteria is really growing within the vents and nothing short of an entire vent swap will get rid of it. From what I heard, Mercedes has an option that will turn off the A/C and blow the vents on High after you shut off the car so that this type of thing doesn't happen. I'm surprised BMW hasn't implemented such a thing. I resorted to doing this manually by turning off the A/C and putting the vents on high as I pulled into a store parking lot or my own garage with my e89 and there were no issues. If it's really bad, you can open the hood, take out the cabin air filter, turn your HVAC on high without A/C, and spray lysol down the vent and hope the lysol kills some of the bacteria.
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08-13-2012, 02:21 AM	#3
juhap Lieutenant 14 Rep 530 Posts Drives: sDrive35i Join Date: Jun 2009 Location: Finland iTrader: (0)	I had this issue too, but it disappeared after a while on its own.
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08-13-2012, 08:51 AM	#4
ymdd Private First Class 17 Rep 107 Posts Drives: not fast enough Join Date: Apr 2012 Location: usa iTrader: (0)	Can BMW do something to fix it?
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08-13-2012, 05:16 PM	#6
ymdd Private First Class 17 Rep 107 Posts Drives: not fast enough Join Date: Apr 2012 Location: usa iTrader: (0)	Has anyone else encountered this ?
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08-13-2012, 08:50 PM	#7
fre2bpowerless Private First Class 5 Rep 129 Posts Drives: Yes. :D Join Date: Dec 2011 Location: India iTrader: (0)	A/c on 'high' temperature for a couple of minutes does the trick for my newer Audi. I do that every few weeks, no such issue on the Z or my F10s
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