Ventilation/Climate Issues with 2010 X5 30i (E70)

[sbordenet]

I have recently bought a 2010 X5. I have some issues with ventilation/climate control for which I cannot find answers. I hope some input from the forum could steer me in the right diretion.

1. The AC just doesn't blow cold. It only blows cool. The refrigerant low pressure side is within specifications. When the auto function is not used, and AC is on max, it blows cool, but part of an upper vent blows tepid. Sometimes the lower driver vent blows hot- REALLY hot. What is going on? Is this the system fighting itself?

2. Does the defrost only blow hot - again, REALLY hot? Even when the AC is on? Is this the only way to address fogging during warm/hot rainy weather? A hot blast in the face isn't bad in winter but is very unpleasant in the spring & summer.

[Qsilver7]

Not sure if you are new to BMWs and truly understand the IHKA control panel/HVAC system.

Make sure you understand BMW's stratified air system. They have been using this set-up for decades...I personally can remember it going back to the late 1970s/early 1980s with the e23/e28/ and possibly e21. The illustration below gives a graphic. The dash vents can be tempered warmer/cooler by using a dial in the middle of the center dash vent in spite of the temp you have selected on the IHKA control panel. This was designed so that the driver could have cooler air blow into their face on long trips to keep them alert, while the passengers remained nice and toasty.

The car will maintain the set temp that is on the control panel...but the driver can make the air from the dash vents warmer or cooler...and the car will still maintain the set temp by changing the temp of the air from the floor or defrost vents. So MAKE SURE that the dial the controls the temp of the dash vents is not turned into the area opposite that you want. When the dial is turned into the red area...warmer air will come from the dash vents (regardless if you have AC on, or heat)...and if you have the dial for the dash vents turned into the blue...then the air from the dash vents will be cooler air (again, regardless if you have AC on or heat).

In regards to the DEFROST...again, check your owners manual to make sure that you are not selecting the RAPID DEFROST/DE-ICE button pressed. This is a pre-programmed button (similar to the MAX button) that will blow heated air at the highest fan speed. Regulated defrost of the windshield and side windows...you use the air direction buttons that allow you to select the defrost vents, dash vents, or floor vents.

Again, refer back to your owners manual to make sure that you understand fully how the system works and that you're using the IHKA selections correctly.

{stratified air illustration from the e38/e39/e53 era}



{stratified air illustration from the e21/e28/e23 era}



{stratified air illustration from the e30/e34/e32 era}

Below are examples of the IHKA control panel from previous gen BMWs...the same applies to your e70. There is a special pre-programmed button for rapid defrost/de-ice that is HEATED air only and the fan speed goes to high...but you should be able to direct air to the defrost vents and be able to select the fan speed you want as well as the temperature:

{e70 IHKA control panel that shows regular defrost and reapid defrost/de-ice buttons}



e39/e53 IHKA control panel that shows regular defrost and rapid defrost/de-ice buttons}



{e38 IHKA control panel that shows regular defrost and rapid defrost/de-ice buttons}

[jclausen]

Have the ac serviced if the pressures are off just a bit it won't work right

[sbordenet]

You are not the first to recommend this. Thanks for the reply.

[sbordenet]

Qsilver7, thanks for the reply. The graphics were helpful - they were not in my manual. Some of your other explanations don't seem to be in my manual - like how RAPID defrost works (heat only).

[Qsilver7]

Qsilver7, thanks for the reply. The graphics were helpful - they were not in my manual. Some of your other explanations don't seem to be in my manual - like how RAPID defrost works (heat only).

No problem. The stratified air distribution illustrations are from BMW Tech documents...so those aren't in the owners manual.

And the defrost vs rapid defrost is not really explained well in the owners manual. If you are a long time BMW owner...it may come easier to understand...as you can see from the previous/older generation BMWs...the basic operating principles are the same even though the IHKA control panel design has changed.

BMW's explanation in the manual doesn't actually say "rapid" anymore...but just eludes to removing ice & condensation "quickly". But when you press the button, it always is heated and the fan is at the highest speed...and you can also press the AC/snowflake button which can also help dehumidify the air.

But the regular defrost/demisting of the windows can be accomplished by using the regular air distribution button...and you can control the air speed and temp...to maintain demisted/defogged windows etc.. Hopefully, this helps explains things or brings more clarity.

{from e70 owners manual - Rapid Defrost/De-Ice button}




{regular defrost - you can regulate fan speed and air temp}

[sbordenet]

Qsilver7, a thermostat question for you. Is the temperature you set on the control panel the cut off temperature for the blower or the mixed temperature of the air being blown from the vents?

[sbordenet]

Qsilver7, a thermostat question for you. Is the temperature you set on the control panel the cut on/off temperature for the blower/HVAC system or the mixed temperature of the air being blown from the vents?

No problem. The stratified air distribution illustrations are from BMW Tech documents...so those aren't in the owners manual.

And the defrost vs rapid defrost is not really explained well in the owners manual. If you are a long time BMW owner...it may come easier to understand...as you can see from the previous/older generation BMWs...the basic operating principles are the same even though the IHKA control panel design has changed.

BMW's explanation in the manual doesn't actually say "rapid" anymore...but just eludes to removing ice & condensation "quickly". But when you press the button, it always is heated and the fan is at the highest speed...and you can also press the AC/snowflake button which can also help dehumidify the air.

But the regular defrost/demisting of the windows can be accomplished by using the regular air distribution button...and you can control the air speed and temp...to maintain demisted/defogged windows etc.. Hopefully, this helps explains things or brings more clarity.

{from e70 owners manual - Rapid Defrost/De-Ice button}




{regular defrost - you can regulate fan speed and air temp}

[Qsilver7]

Qsilver7, a thermostat question for you. Is the temperature you set on the control panel the cut off temperature for the blower or the mixed temperature of the air being blown from the vents?

Yes. On the IHKA (auto climate system)....there is a temp sensor located on the IHKA control panel. Prior to July 2012...there's a small fan inside the IHKA control panel that draws air in through a vent/grid/grill (in the panel) and passes it across a thermistor.

Starting with 7/2012 production, BMW started changing the IHKA control panels and exchanged the forced air engineering to a little rubber looking button (which is actually a temp sensor). This change helped reduced the collection of dust on the vent/grid where air was sucked inside the control panel...as well as stop the collection of dust inside the control panel and on the little fan inside, as well.

{note the little rubber button below the AUTO dial in pic below...this is the newer styled temp sensor BMW started implementing on the IHKA control panels starting around 7/2012}

The system maintains the temperature you set on the IHKA control panel by measuring the temperature of the air inside the cabin. So, depending on how you have thing set-up (complete auto mode incl fan & air distribution...or manual selection of air and/or fan speed...as well as stratified air selection to the blue or red area)...the IHKA system will either heat or cool air from other vents and either increase or decrease fan speed to maintain the temperature you have set. If you have front & rear heating systems..then there are additional temp sensors for the rear IHKA control panel that will adjust the blower and air distribution for the rear based on the set temp on the control panel. If you press the ALL or SYNC button on the front IHKA control panel...then either both sides or front & rear systems will maintain what is set for the front driver's settings.

In the illustration below #17 shows the location of the vent/grid where the fan inside sucks air into the control panel...or the location of the (external) temp sensor starting with 7/2012 build date up.