[ybkbmw]

Greetings!

Does anyone have any idea and/or noticed a phenomena in title? I recorded videos while manipulating fresh air control and AC buttons and listening to a blower fan noise and can post them here if needed. More noise means interior air. With AC on system immediately switches to interior air regardless of fresh air control button LEDs.

While checking six random 2014 F30s I found three of them behaved this way and three others followed owner's manual.

May I ask readers to check their F3Xs to see if fresh air control works with AC on?
Thanks!

[328iX]

Press and hold the button

[ybkbmw]

What do you mean by press and hold the button? When I turn AC on the system switches to interior mode based on the increased fan noise. Pressing the fresh air control button makes no difference whatsoever except for changing LEDs from A to M to off and clearly heard click like sound when system supposed to switch to fresh air.

[Billfitz]

Originally Posted by ybkbmw

When I turn AC on the system switches to interior mode based on the increased fan noise.

I doubt that you can tell that it's in recirculating mode just by the sound. In normal operation it's not in recirculating mode, and will only do so if you push the recirculate button and see the LED light up.

[ybkbmw]

Originally Posted by Billfitz

I doubt that you can tell that it's in recirculating mode just by the sound. In normal operation it's not in recirculating mode, and will only do so if you push the recirculate button and see the LED light up.

It is unbelievable easy to tell. Put fan on max in manual mode, keep AC off. push button to M LED, pay attention to a loud air flow sound from front passenger area. Then push it once again to no LEDs and notice significantly less air flow sound when system switches to fresh air mode.

Please repeat the same with AC on during hot weather and report here. I personally checked six random 2014 F30s and only three of them worked as manual says.

[Wires]

Blower does it's own magic depending on the AC core temp. If you had the fan really low when it's hot outside, the core will start to freeze up, and then it would close valves in the dash to cycle air across the core to thaw it out.

Is this what you are seeing? Could be an overcharge on the AC system as well that is causing the above.

[eluded]

Originally Posted by Wires

Blower does it's own magic

This. It's German so the car knows best.

[Icarium81]

Semi related question.wtf do those things mean on the A/M button?

[ybkbmw]

Originally Posted by Wires

Blower does it's own magic depending on the AC core temp. If you had the fan really low when it's hot outside, the core will start to freeze up, and then it would close valves in the dash to cycle air across the core to thaw it out.

Is this what you are seeing? Could be an overcharge on the AC system as well that is causing the above.

Not really. Start without AC on a hot day, cycle fresh air control to make sure flap is working, confirmed by louder air flow sound in M mode. Make sure no LEDs are on - fresh air mode, then hit AC button. Noise is immediately changes indicating interior air, same sound as in M mode. Fresh air control has no effect then.

UPD: please test your 340 and post results.

[ybkbmw]

Originally Posted by Icarium81

Semi related question.wtf do those things mean on the A/M button?

[1KWIKBMR]

Originally Posted by Icarium81

Semi related question.wtf do those things mean on the A/M button?

Auto/manual/open (no LEDs) for the fresh air vent.

[ybkbmw]

Could any 3-series owner reading this topic, seems to be many, please try to verify if fresh air control works with AC on on a hot day?

Test described here https://f30.bimmerpost.com/forums/sh...31&postcount=9

[ybkbmw]

This topic has been read 400+ times and got exactly zero answers on a very simple request to verify and report fresh air control function.

Anyone, please!

[Wires]

It's most likely working "as per design". Leave your AC on as engineered, and it will work the way you expect it to. There is ZERO reason to ever turn it off.

What you are experiencing is most likely the car drying the core with recirculated air when you turn on the AC, or accelerating the cool down of the cabin.

Don't worry about it, you clearly have stated to have seen this on multiple cars.

[gIzzE]

Originally Posted by ybkbmw

This topic has been read 400+ times and got exactly zero answers on a very simple request to verify and report fresh air control function.

Anyone, please!

With the climate control off (remember climate on these cars not old style air con) it will open the fresh air flaps 100% if you are asking for cold air and have recirc off.

With it on it would close them as needed to make sure the temperature required is what you are getting. Open the flaps 100% with 80f ambient air coming in and the system will have a hard time keeping your cabin at 68f or whatever you set it at.

We work in ºC over here, so guessing ºF numbers.


What exactly is the problem? Apart from you not liking the way it is designed to work? Surely set it to 68ºf and forget?

I never touch it summer or winter. 21ºc and leave it.

[ybkbmw]

Originally Posted by gIzzE

With the climate control off (remember climate on these cars not old style air con) it will open the fresh air flaps 100% if you are asking for cold air and have recirc off.

With it on it would close them as needed to make sure the temperature required is what you are getting. Open the flaps 100% with 80f ambient air coming in and the system will have a hard time keeping your cabin at 68f or whatever you set it at.

We work in ºC over here, so guessing ºF numbers.


What exactly is the problem? Apart from you not liking the way it is designed to work? Surely set it to 68ºf and forget?

I never touch it summer or winter. 21ºc and leave it.

I am fine with ºC, no need to guess ºF, thank you. What I would like 3 series owners to check is what shown on these videos

https://vimeo.com/440448788
https://vimeo.com/440448893
https://vimeo.com/440449068

The problem is that with AC on I have no fresh air, even if fresh air control set to unconditional fresh air on, according to factory manual and TSBs. As I mentioned earlier, out of six cars tested three had no fresh air with AC on.

Thank you.

[ybkbmw]

Originally Posted by Wires

It's most likely working "as per design".

It can't be "as per design" because it contradicts the driver's manual clause don't drive with interior air only for extended period of time to avoid bad odor and window fogging. I am getting exactly that.

Originally Posted by Wires

Leave your AC on as engineered, and it will work the way you expect it to. There is ZERO reason to ever turn it off.

I don't turn AC off. I don't want AC to turn fresh air off for me and force me breathing interior air and experience windows fogging. Why some cars do it and some don't in the same exact weather conditions after seating on the parking lot next to each other?

Originally Posted by Wires

What you are experiencing is most likely the car drying the core with recirculated air when you turn on the AC, or accelerating the cool down of the cabin.

There is ZERO reason to dry the core when on 35C day you start the car after it was sitting under the sun for several hours. Could there be other reasons why fresh air control is ignored? When a car left under the sun for a long time the temperature inside is way more then outside. "Accelerated cool down" process actually means push interior air out as quickly as possible first. Instead many automatic AC system stubbornly try to cool 40C+ interior air instead of pulling much colder 30C air from outside first. 3-series cars have an option to manually force exterior air in first but something prevents it from working on a half of cars tested.

Originally Posted by Wires

Don't worry about it, you clearly have stated to have seen this on multiple cars.

Yes, a half of cars tested worked as manual says and other half did not.

On the videos in previous post I can clearly hear a click like sound when control is switched from interior to exterior air as if something is attempting to move the flap but fails.

[gIzzE]

Try it again when it is 10ºc outside, you will get the results you want.

By the way, steamed up car will happen far more with fresh air and no climate. The climate works as a dehumidifier.


The BMW climate system works incredibly well, set the centre vent to blue and then adjust the temperature, you will get as much 'fresh' (read that as hot ambient) air as the system can handle to keep the temperature required with the lowest possible fan speed.

On older BMWs you got more 'fresh' air but the fan and air con often had to be worked much harder to keep the temperature down.
This system allows you to keep the cabin at 19ºc with the fan hardly going, even when it is 35ºc outside.
Hence why you now adjust fan speed manually on the F30 while the rest of the system is auto.


Just one thing. Is your climate ice cold? Like almost brain freeze with it blowing in your face with the fans on full?
Is the system also really powerful in the amount of air it kicks out? Like properly powerful on full blast with the centre vents pointed at you?

[gIzzE]

I reckon your refrigerant gas is low, the system has some fail safe measures that start to kick in when the pressure in the system drops below a certain level, 31psi for the e90 series.

Not opening/closing certain flaps, reducing fan speed, only aiming climate at driver side while only ambient air at passenger side, etc. etc.

I would get to an AC specialist and get them to test it. Someone who knows BMW systems, which is not BMW.

I had this the other month, BMW were useless, kept saying it was 30psi so fine, I kept saying it is not and just do a regass, they wouldn't. Took it to my local place and the guy there said "Making a whirring noise or not all flaps opening? Seeing this more and more with modern systems."

20 mins later all working perfectly and still working perfectly now.

[ybkbmw]

Originally Posted by gIzzE

Try it again when it is 10ºc outside, you will get the results you want.

Negative, I was able to catch this behaviour when it was as low as 12ºC outside.

Originally Posted by gIzzE

By the way, steamed up car will happen far more with fresh air and no climate. The climate works as a dehumidifier.

May be but I want full control. If manual says that no LED == 100% fresh air I am fully expecting that. My other, different brand but same luxury level, car has similar button and it works 100% of the time regardless any conditions.

Originally Posted by gIzzE

The BMW climate system works incredibly well,

May be by design but definitely not in my case.

Originally Posted by gIzzE

set the centre vent to blue and then adjust the temperature, you will get as much 'fresh' (read that as hot ambient) air as the system can handle to keep the temperature required with the lowest possible fan speed.

On older BMWs you got more 'fresh' air but the fan and air con often had to be worked much harder to keep the temperature down.
This system allows you to keep the cabin at 19ºc with the fan hardly going, even when it is 35ºc outside.
Hence why you now adjust fan speed manually on the F30 while the rest of the system is auto.

I can't comment on this. It seems to me that BMW tech themselves don't know how the system works. Factory keeps it under "top secret" label.

Originally Posted by gIzzE

Just one thing. Is your climate ice cold? Like almost brain freeze with it blowing in your face with the fans on full?
Is the system also really powerful in the amount of air it kicks out? Like properly powerful on full blast with the centre vents pointed at you?

It is way too cold. Even when set to 23ºC I get as you said brain freeze blowing in my face.

[ybkbmw]

Originally Posted by gIzzE

I reckon your refrigerant gas is low, the system has some fail safe measures that start to kick in when the pressure in the system drops below a certain level, 31psi for the e90 series.

Not opening/closing certain flaps, reducing fan speed, only aiming climate at driver side while only ambient air at passenger side, etc. etc.

I would get to an AC specialist and get them to test it. Someone who knows BMW systems, which is not BMW.

I had this the other month, BMW were useless, kept saying it was 30psi so fine, I kept saying it is not and just do a regass, they wouldn't. Took it to my local place and the guy there said "Making a whirring noise or not all flaps opening? Seeing this more and more with modern systems."

20 mins later all working perfectly and still working perfectly now.

If you saw my videos, would you be so kind to perform the same test when its 25C or more outside? Some people did say that this is expected behaviour but I myself found it not consistent among several vehicles so one way or another it is definitely not expected.

[Wires]

Are you sure you are comparing multiple identical cars (same software, same refrigerant pressure, etc). I bet you are not.

BTW, I wouldn't use the users manual as the bible for how it should work. Things get written down, issues are found, software is changed, the manual does not. Most times the manual is a cut/paste from previous models and not always 100% current.

For the record, the car will ALWAYS cool faster with recirculated air than pulling in outside air. You get higher air flows since there is no restriction, and the rate of temperature drop is higher. EVERY car has a "MAX AC" button that does this, since the beginning of time. It is all a matter of thermodynamics.

You seem to be fixating on a weird corner case that you need to jump through hoops to replicate. Get the car updated to the latest ISTA level, have the refrigerant levels checked, and then tell us if it still happens.