[CnoteMD]

In the manual it says that if the first green light is active on the recirculation button, it will "sense" increased pollutants and automatically turn on the recirculation mode. After the air has "cleared", it will go back to normal mode. However, I have never seen any change in the display to let me know if it is normal vs. recirculation mode.

I remember when I test drove a Lexus GS a while back, I drove behind a bus and the air inside the car stayed fresh. There was also a visual confirmation (the recirculation button on the dash changed) to let me know it was active.

Lately when driving through the Lincoln tunnel, if I don't manually change the setting to permanent recirculation, I will suffocate from the diesel fumes. I don't know if my auto-reciculation isn't working or if this feature just doesn't work as well as other car companies feature.

Any input would be appreciated.

[E90Fleet]

Ive never seen the indication change on any BMW ive driven
But i do know its gone into recirculation mode often

[Atty]

It does work, but its reactive, not proactive. That means you will smell pollutants for a sec until the car realizes it smells and switches over to recirc.


If you anticipate some bad stink ahead of you, you should choose the manual recirc override.

It's really too bad it's not more proactive. I change it myself as soon as I smell exhaust, etc.

[Black325i]

According to the manual, it can only detect noxious fumes. So, if skunk or, heaven forbit, someone lets a huge fart go, the auto recirc won't help you out...

Personally, I keep mine on auto, but never really notive any change.

Now what would be cool is an interior sensor, so when you let one rip, you don't have to tip the others off by opening a window

[poldim]

Originally Posted by Black325i

According to the manual, it can only detect noxious fumes. So, if skunk or, heaven forbit, someone lets a huge fart go, the auto recirc won't help you out...

Personally, I keep mine on auto, but never really notive any change.

Now what would be cool is an interior sensor, so when you let one rip, you don't have to tip the others off by opening a window

hahahahhaha, you need to sign up for the class mentioned in this post:
http://www.e90post.com/forums/showpo...81&postcount=5

[BMW0]

I was wondering about the Auto Circulation button. Nice to know that its delayed. I did smell a hint of diesel fumes (diesel cars are the popular choice due to expensive gas prices) while set on the Auto Circ button so I keep it on Circulation when I anticipate a bus or see black smoke bursting through tailpipes straight ahead.

[poldim]

I just switch it on when I see something stinky ahead....otherwise it fogs up the windshield...

[billgti]

i too find the auto recirculate function not too effective. i tend to smell the fumes and manually switch to recirculate asap so i really don't know if it's just slow to switch or if it isn't working at all. maybe next time i'll try letting the auto do it's work...

[Atty]

Also, if you have iDrive, you can program one of the steering wheel buttons to serve as a remote button for the recirc switch. Thus, if you are too lazy to move your hand over about 1 foot to the right, you can control it right there.

[CnoteMD]

Thanks for the feedback. I didn't want to waste a trip to the service department for something that apparently is working correctly.

However, it makes me wonder what is considered a "pollutant" and just how much it takes to set off the sensors. I would think that diesel exhaust thick enough to cloud your vision (if you've been stuck in traffic in any of the NYC tunnels, you'd understand) would set off the sensors. On a few occasions, I have tested the system by leaving it in auto-recirc mode and my car smelled like exhaust for the entire time I was in the tunnel (about 15 minutes or so). If I manually switch to recirc, the air clears within a couple of minutes.

Maybe due to the higher prevalance of diesel cars in Europe, this is considered normal air for BMW's

[Schweitzer]

Aren't there two modes of recirc? If I recall, there's a circle and a circle with an A in it? I'm in my office and can't run out to check, but I was wondering what the difference in modes was.

[Yobyot]

Originally Posted by Black325i

According to the manual, it can only detect noxious fumes. So, if skunk or, heaven forbit, someone lets a huge fart go, the auto recirc won't help you out...

Personally, I keep mine on auto, but never really notive any change.

Now what would be cool is an interior sensor, so when you let one rip, you don't have to tip the others off by opening a window

I wouldn't need this feature because, frankly, mine don't stink.

Instead, it's the smell of freshness, the great outdoors and home cookin'.

[CnoteMD]

Originally Posted by Schweitzer

Aren't there two modes of recirc? If I recall, there's a circle and a circle with an A in it? I'm in my office and can't run out to check, but I was wondering what the difference in modes was.

The circle with the A is the automatic mode. This is supposed to allow outside air to enter the car under normal circumstances, but change to recirculation mode when there are high levels of polutants in the outside air.

The plain circle is also recirculation mode, but this one is permanent. There will be no air from the outside entering the car. The problem with this mode is that if you leave it on for too long, the windows will begin to fog.

If both lights are off, then outside air will always enter the car.

[ex-poster]

I've read that the sensor is "tuned" to detect diesel fumes. However, I've had it work well on lots of smoke and fumes. Unlike others in this thread, mine has worked pretty well, both on the E90 and the E46, being able to drive into smoky environs with only a hint of the bad air.

Originally Posted by CnoteMD

Thanks for the feedback. I didn't want to waste a trip to the service department for something that apparently is working correctly.

However, it makes me wonder what is considered a "pollutant" and just how much it takes to set off the sensors. I would think that diesel exhaust thick enough to cloud your vision (if you've been stuck in traffic in any of the NYC tunnels, you'd understand) would set off the sensors. On a few occasions, I have tested the system by leaving it in auto-recirc mode and my car smelled like exhaust for the entire time I was in the tunnel (about 15 minutes or so). If I manually switch to recirc, the air clears within a couple of minutes.

Maybe due to the higher prevalance of diesel cars in Europe, this is considered normal air for BMW's

I consider this kind of performance unacceptable, and mine performs the same as described above.

[Thavash]

I once drove behind a truck , and could smell the diesel fumes. So I don't think it works that well. The good thing is that BMW puts a button on the steering wheel to change the circulation mode, so when you see a truck coming you can quickly change it.