[mem_cg]

Good morning guy we noticed the ac system throws warm air or hot air through the footwells and the rear vents....front vents is cold but It does get warmer as you keep driving (30 min or so) been talking to the dealer and they said its normal for this car. I have setting at 68 degrees they said to run it as manual not auto. Is this normal? All my other BMWs dont do this.

[mreg376]

Well, you don't say what vehicle it is, and you don't say whether you're trying to cool or warm the cabin.

[mem_cg]

Sorry its x3 m40i i am trying to cool the cabin have the ac system on...... basically cold air comes from the front vents hot/warm air from foot vents...... if i put all the air to come put of footvents only hot/warm air comes out.... i change to front vents its cold air again

[JK2018]

This happened to me last month.. My wife sitting at the back was like "are you trying to kill me???" and I had no idea what she was talking about until I put my hand over the vent.... Now I don't know how long it's been like that because no one sits at the back.... Restarting the car did not help but shutting all electrics off b4 you shut off engine, it helped.

[HighlandPete]

Have you got the 3/1-zone system?

If so check out the rear settings. Make sure you are trying to cool the rear.

[kv1980]

Originally Posted by mem_cg

Good morning guy we noticed the ac system throws warm air or hot air through the footwells and the rear vents....front vents is cold but It does get warmer as you keep driving (30 min or so) been talking to the dealer and they said its normal for this car. I have setting at 68 degrees they said to run it as manual not auto. Is this normal? All my other BMWs dont do this.

My car does the same. I just have it since a few weeks so I didn't mention it to the dealer yet. It is rather strange...

[satz]

Has the dealer checked the AC refrigerant level in case any has leaked?

[kv1980]

Originally Posted by satz

Has the dealer checked the AC refrigerant level in case any has leaked?

The problem is not cooling...the problem is that the front vents always blow cold air even when the heating is on...warm air (from heating) only comes from the vents at the footend...

[mem_cg]

Its very frustrating..... their response is put it on max ac and only manual mode...... all my cars are always set at 68-70 and i am freezing....now i noticed when manual mode ac running only on front vents i get cold air once i switch it to foot vents i get warm air not cold air. I switch it to front vents again and cold air again. As i keep driving the cool air gets warmer and warmer to a point where the air outside is colder than the inside of the cabin. This takes about 30-40 min of driving.... Also, when i have it on both front vent and foot vents i get cold air on top and warm air in the bottom lol and to top it off i had four quartz of oil added under 4700 miles two at 3800 and two at 4700

[mem_cg]

Originally Posted by HighlandPete

Have you got the 3/1-zone system?

If so check out the rear settings. Make sure you are trying to cool the rear.

Yes sir i have it on sync mode with the front

[titomi]

There is a setting for the front central vents in the AC menu. Try to fiddle with that. Say put in on cold a observe what kind of air is coming from the footwell vents. I would say it affects what kind of air is coming from all vents. It doesn't have to be the same temperature everywhere.

[HighlandPete]

Originally Posted by titomi

There is a setting for the front central vents in the AC menu. Try to fiddle with that. Say put in on cold a observe what kind of air is coming from the footwell vents. I would say it affects what kind of air is coming from all vents. It doesn't have to be the same temperature everywhere.

Agree.

Need to eliminate the possibility is is the face level settings influencing the outlet temperatures. Certainly what I'd be trying.

[satz]

does adjusting the hot/cold 'blend' setting do anything?
When I have that on warm, then the face vents always blow warmish air.

When I have it on the cold side, it's the opposite. It seems to affect the face vents, and not the foot and floor vents.

[tapochek]

To revive an old post, but did you ever get an answer on this?

I just found out that my rear vents blow HOT air no matter what I set the air con to. The front vents and footwell will be ice cold, but the rears will be sweltering hot.

[GGEVOX]

I have personally owned 5 new bmws in the last 10 years. Everyone has had an issue with the AC on really hot days. I thought i remember the dealer saying the AC condenser lines/sensor freezes over and gives false readings. I remember some days driving on the highway that my wife and I can not be in the car anymore because its so hot. Dealer tells me to pull over and let the unit thaw for a few minutes. Usually works but its amazing that so many different models of BMW's do this. Hate it.

Never happen in cold days. Only really hot days. And only when AC is being used.

[MX330I]

Happened to me. It threw a code. Something like rear air mix flaps /motor stuck. Read your codes and see what it says.

[lxlxlx]

Originally Posted by MX330I

Happened to me. It threw a code. Something like rear air mix flaps /motor stuck. Read your codes and see what it says.

No code, but dealer recalibrated the flap motors and that didn't fix it. Although occasionally something behind the dashboard makes a mechanical clicking noise when the AC is on.

[MX330I]

Originally Posted by lxlxlx

No code, but dealer recalibrated the flap motors and that didn't fix it. Although occasionally something behind the dashboard makes a mechanical clicking noise when the AC is on.

Yes, mine was also making weird clicking noises for several months before the hot air started blowing from rear air con. But my dealer just replaced the motor and it fixed it. When I brought it in earlier complaining about the clicking noise, they said it was normal. It's definitely a stuck flap in the air mixer, and it's best to replace the motor.

[benr]

Had a similar issue in my X3 xDrive 30i. The rear ventilation would on some journeys be at maximum temperature, and nothing could be done to stop the air coming out hot. For example, even with A/C on and the rear controls at the lowest temperature, hot air would still flow through the foot well and rear central vents. However on the next journey, everything would be fine.

Took it to the dealer as still under CPO warranty. They reported "Mixing flap for rear air faulty. Connected battery charger and checked fault memory. Had fault 801127. Followed test plan and found mixing flap failed. Replaced mixing flap for rear air. Addressed motors and calibrated. Cleared fault and test ok". the line item itself state "replaced controller drive of the air mixing flap, rear" with the part given as 64-11-9-384-023 Actuator:644021

I've only had it back 1 day, but so far, so good.

[Chief Orman]

Originally Posted by GGEVOX

I have personally owned 5 new bmws in the last 10 years. Everyone has had an issue with the AC on really hot days. I thought i remember the dealer saying the AC condenser lines/sensor freezes over and gives false readings. I remember some days driving on the highway that my wife and I can not be in the car anymore because its so hot. Dealer tells me to pull over and let the unit thaw for a few minutes. Usually works but its amazing that so many different models of BMW's do this. Hate it.

Never happen in cold days. Only really hot days. And only when AC is being used.

Had the same issue on my 335d.

[Goldiegee]

There was another thread on here about changing the cabin air filter. If this is not done correctly it can damage the flaps or jam them in the wrong position. Have you had a change recently, it could be that?

[freshxdough]

Originally Posted by Goldiegee

There was another thread on here about changing the cabin air filter. If this is not done correctly it can damage the flaps or jam them in the wrong position. Have you had a change recently, it could be that?

Doesn't cause issue with warm air coming from vents with AC on