Z4 Blowing only hot air, at random

[wildag]

My Z4M has this little bug where the air conditioning system will go into a "blow only hot air" mode. It happens randomly, about 3 times a week. Only shutting off the car for 20 minutes will fix the situation.

The dealer has replaced the IHKA (ac control) module, but the problem remains. They tell me that the IHKA module reports that it can't control the internal duct doors that direct air to the console vents. The module then goes into an "emergency" mode where it ensures that hot air is available to melt snow/ice off the windshield if necessary.

Has anyone else had a similar problem?

[Huz-Z]

Did a politician own it at some point?

And to be serious, no, I have not had this problem. I wonder, the inability to control the duct doors - could it be that something has gotten lodged in the mechanism preventing the doors from operating correctly?

[wildag]

Originally Posted by Huz-Z

Did a politician own it at some point?

And to be serious, no, I have not had this problem. I wonder, the inability to control the duct doors - could it be that something has gotten lodged in the mechanism preventing the doors from operating correctly?

I know that they've had the center console apart, so I assume that they'd have investigated that. I may get up under there myself if the they can't figure out something today.

[chickdr]

Originally Posted by wildag

I know that they've had the center console apart, so I assume that they'd have investigated that. I may get up under there myself if the they can't figure out something today.

What is the dealers next move? The car is under warranty and your AC system is malfunctioning. They need to figure it out. Sounds like they need more time. I wouldn't spend any of my own time on it when the car is under warranty... Get a loaner until they fix it.

[wildag]

Originally Posted by chickdr

What is the dealers next move? The car is under warranty and your AC system is malfunctioning. They need to figure it out. Sounds like they need more time. I wouldn't spend any of my own time on it when the car is under warranty... Get a loaner until they fix it.

Oh yea, they'll be catching heck from me, through BMWNA, if its not fixed with this round of service. But because they seem to be completely incapable of identifying the issue, and I'm driving a car that's constantly 90 degrees inside, I'm willing to try my own hand.

I'm waiting for a loaner right now. They say 3 - 4 hours for the waiting list

[Huz-Z]

It certainly seems that the dealer should replace the entire system for you to eliminate the problem.

[Valarr]

No help but one of the gremlins in my car will randomly take control of the vent controls. It will decide @ random which vents to blow air out of- the controls do nothing when it occurs. It switches randomly between vents.
Happened 2x now.

Another gremlin controls the heat/cold and will only permit cold air to be emitted until the temp control knob is switched back to cold then later to hot.



My conclusion? It's either cursed or infested by gremlins.


So, subscribed in case you post a solution (I'm thinking the problems are similar).

[hansaysso]

I had this same problem in my Z4MC. I took it into the dealership, they gave me a loaner, and the next day problem solved. Sorry if it isn't helpful at all, but they did this all under warranty.

[wildag]

Originally Posted by hansaysso

I had this same problem in my Z4MC. I took it into the dealership, they gave me a loaner, and the next day problem solved. Sorry if it isn't helpful at all, but they did this all under warranty.

Would you mind calling up your dealership and getting a summary or work order that explains what they did? I'd appreciate it very much!

[chickdr]

Originally Posted by hansaysso

I had this same problem in my Z4MC. I took it into the dealership, they gave me a loaner, and the next day problem solved. Sorry if it isn't helpful at all, but they did this all under warranty.

No paperwork when you picked up the car? It should list what was done(parts replaced, ect.) to fix the issue.

[wildag]

Got the car back from the dealer. They said that the tech found a broken motor for one of the internal ducts. I don't know why they couldn't have found this during one of the last three times I had a tech look at the car. The air coniditioning system operated normally on my drive home.

Replaced so far...

IHKA Module
Passenger's side footwell stepper motor

If I don't update this thread in the future, that means the problem has been fixed.

[hansaysso]

sorry that I didn't get back to you. Paperwork wise same things as you have already listed were replaced.

IHKA Module
Passenger's side footwell stepper motor

anyone else have this issue? it may be a factory faulty part?

[chickdr]

Interesting that both cars received exactly the same fix. Must be a common issue. I will remember this thread.

[Lucky1]

Originally Posted by wildag

Got the car back from the dealer. They said that the tech found a broken motor for one of the internal ducts. I don't know why they couldn't have found this during one of the last three times I had a tech look at the car. The air coniditioning system operated normally on my drive home.

Replaced so far...

IHKA Module
Passenger's side footwell stepper motor

If I don't update this thread in the future, that means the problem has been fixed.

I get no air directed to the console vents either but all other vent directions are working fine. Assume I can replace this same motor and problem will be fixed? Can anyone comment?