BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   ZPOST > BMW Z4 Roadster and Coupe > General BMW Z4 Forum

Post Reply
Thread Tools Search this Thread
      11-18-2010, 09:31 PM   #1
First Lieutenant

FerRrari's Avatar
Drives: Catrinel Menghia
Join Date: Sep 2010
Location: WA

Posts: 389
iTrader: (1)

A/C blowing only hot air?

Has anyone experienced their A/C only blowing really hot air even if the temp is set all the way to cold? It has happened twice with my Roadster but it goes away after a while so the dealer cannot reproduce the issue.
'12 Nero/Rosso 500 Abarth
'07 IR/SBL ///M Roadster (GONE), '08 Tornado Red Triumph Daytona (GONE), '09 BRG/Cloth 6MT MINI Cooper S (Spontaneously Combusted), '06 IR/IR ///M3 Convertible 6MT (GONE), '04 JB/CR Z4 2.5i SMG (GONE)
Appreciate 0
      11-18-2010, 10:17 PM   #2

rps's Avatar
Drives: 2013 X1
Join Date: May 2009
Location: Pace, Fl

Posts: 457
iTrader: (11)

Had the same problem, they wound up replacing the entire climate control assembly.
NB8S Gone but not forgotten: 2006 Z4, 2008 135i replaced with a 2013 X Drive X1
Appreciate 0
      11-19-2010, 07:00 AM   #3
Flying Scotsman
Private First Class

Flying Scotsman's Avatar
Drives: BMW Z4 2.5L
Join Date: Jan 2010
Location: Long Island N.Y.

Posts: 146
iTrader: (0)

Appreciate 0
      11-20-2010, 09:49 AM   #4
Enlisted Member

Drives: 07 Z4 Coupe
Join Date: Jul 2010
Location: Oklahoma City, OK

Posts: 38
iTrader: (1)

When my battery died over the winter time I had to have my A/C and the windows automatic function reset. The battery drained twice from a lack of driving and I had to have it reset each time. Not sure if this will help since the problem clears up on its own and then returns.
Appreciate 0
      11-20-2010, 11:15 AM   #5
///M'n it Up

wildag's Avatar
Drives: '06 ///M Roadster
Join Date: Aug 2009
Location: Reston, VA

Posts: 310
iTrader: (0)

Originally Posted by FerRrari View Post
Has anyone experienced their A/C only blowing really hot air even if the temp is set all the way to cold? It has happened twice with my Roadster but it goes away after a while so the dealer cannot reproduce the issue.
I had the exact same issue. Took my car to the dealer several times when the issue reared its ugly head, but of course they were always busy with no immediate availability. And when I took the car back, they couldn't reproduce the issue, even though the service advisor had seen it in person several times.

In the process of taking "pot shot" attempts at fixing this problem, they replaced the IHK module and down graded the firmware on that module. That didn't have any affect on the problem.

They finally fixed the issue by replacing the stepper motors that control the air vent flaps under the dash. They found that the passenger side foot well flapper motor was completely worn and shorted. The problem has not returned since.

The explanation of the problem is pretty straight forward. When the the IHK (A/C module) detects that its unable to control any one part of the A/C system, it goes into a "safety mode". The safety mode is hot air only, with all possible flaps pushing air to the windshield, and manual control of the fan. This ensures that you can drive the car in icy conditions.

What I deduced after having the issue fixed is that in fact, its very easy for a technician to find the logs of this occurring in the IHK. But because the techs either don't know about it, or are too lazy to try it, the simple diagnosis is done.

I've read of several others on other forums having this problem, and at least two of those were also fixed by replacing the passenger side foot well vent flap motor.

I believe the part they replaced was number 3 in the following diagram.


DreamingWell.com Web Services

Last edited by wildag; 11-20-2010 at 11:24 AM.
Appreciate 0
      11-21-2010, 08:27 PM   #6

Drives: 2005 Z4 Roadster
Join Date: Sep 2008
Location: Canada

Posts: 56
iTrader: (1)

Happened to me. Had to get the A/C compressor replaced.
Appreciate 0
Post Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -5. The time now is 07:59 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST