BMW Z4's AC System Completely Dead, Fix Needed

I had a similar issue with my 2012 BMW M3 last summer. The AC system completely shut down, just like yours. Turned out to be faulty valve solenoids in the AC system, two of them were stuck and not regulating the refrigerant flow properly. When I took it to the garage, they first did a pressure test which showed the system wasn't cycling correctly. After a deeper diagnostic, they found those defective valves were causing the whole system to fail. The repair involved replacing the valve solenoids and doing a complete refrigerant recharge. It was a serious repair that took two days to complete, mainly because they had to partially disassemble the dashboard to access some components. Not a DIY job for sure, you need specialized equipment and knowledge of BMW AC systems. The good news is that once fixed, it's been working perfectly for over a year now. Given your Z4's mileage, it could be the same issue. Just make sure whoever works on it has experience with BMW cooling systems.

Thanks a lot for sharing your M3 experience, this sounds very similar to my problem! Really helpful to know about those valve solenoids, especially since my symptoms match exactly what you described. Good to hear it's fixable, even though it seems like quite an involved repair. Do you happen to remember roughly how much you paid for the whole job? Also, has everything stayed working properly since then, or have you noticed any other AC-related issues pop up?

Hey there! Happy to give you an update about the costs. I ended up paying 1000 € for the entire repair, that covered replacing those troublesome valve solenoids and getting the whole system recharged. I know it sounds steep, but considering the complexity of BMW AC systems and all the work involved, it was worth every cent. And I've got great news, since getting it fixed, my AC has been working absolutely perfectly. No more issues whatsoever. It's actually blowing even colder than it did before the problems started. The airflow is great, and everything's been running smoothly for over a year now. It's such a relief not having to worry about it anymore, especially when the weather gets hot. Trust me, while the repair bill might make you wince a bit, getting it properly fixed by someone who knows what they're doing is definitely the way to go. These valve problems don't fix themselves and usually just get worse if you leave them. Sounds like you've got the same issue I had, so hopefully this helps with your decision!

Thanks for all the details about the costs and the follow-up info! I bit the bullet and took my Z4 to a specialist mechanic yesterday. You were spot on, it was exactly the same valve solenoid issue. What a relief to finally know what was wrong! The repair cost came in slightly higher than yours at 1200 €, but they also found and fixed a minor refrigerant leak while they were at it. Just got the car back today and wow, what a difference! The AC is blasting cold air like it's brand new. Even the airflow seems stronger than before. Really appreciate you sharing your experience, it gave me the confidence to get it sorted properly instead of trying cheaper fixes that probably wouldn't have worked. No more sweating in traffic for me! Thanks again for all your help with this!