BMW Z4 Stalling: Secondary Air Pump Warning Signs

Hey there! I had almost identical issues with my 2020 BMW M440i last month. The jerking and stalling were spot on similar to what you're describing. After a thorough inspection at the garage, they found the hose connection between the secondary air pump and the air valve was damaged, causing inconsistent air flow. The fix involved replacing both the hose and the connection ports as they had developed micro-cracks. While the repair wasn't particularly complex, leaving it unfixed could've led to more serious engine damage down the line. The check engine light was clearing intermittently which made diagnosis tricky at first. My advice would be to get it checked soon, this isn't something you want to leave unattended, especially with those symptoms. The secondary air system is crucial for proper engine function and emissions control. Took about half a day to fix once they identified the problem. Hope this helps with your decision.

Hey, thanks for sharing your experience! I've been looking around and it seems like the secondary air system issues on BMWs are more common than I thought. You're lucky they caught it early with just the hose and connection ports needing replacement. By the way, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since the fix, or have you noticed any other quirks? My car's going in next week, so I'm trying to get a better idea of what I might be dealing with. Really appreciate the help!

Hey again! Happy to give you an update! Since my last message, I can confirm everything's been running perfectly smooth with my M440i. The repair was totally worth it, cost me 175€ for fixing that faulty hose connection from the pump to the valve. Not too bad considering what could've happened if left unchecked! The jerking and stalling completely disappeared after the fix. It's been about six weeks now, and the engine's purring like it should, no check engine lights or any other weird behaviors. The mechanic mentioned I caught it at the right time before it could cause any serious damage to other parts. Just a heads up for your upcoming appointment, make sure they thoroughly check the connection ports too, not just the hose itself. Sometimes they can look fine but have tiny cracks that cause all sorts of issues. Trust me, you'll notice the difference right away once it's fixed. Let me know how it goes next week! Always good to share experiences with fellow BMW owners.

Thanks so much for all the details! I actually just got back from the mechanic today. What a relief, turns out you were spot on about those connection ports! Had mine checked out and they found hairline cracks, just like you mentioned. The mechanic did a thorough job, replaced both the hose and ports, and even gave the whole system a good inspection. Bill came to about 200 bucks, a bit more than yours but still reasonable considering what could've gone wrong. The best part? My Z4's running like a dream now! No more jerking or stalling, and that pesky check engine light is finally off. It's amazing what a proper fix can do. Should've done this weeks ago instead of worrying about it. Really grateful for your help, saved me from a potentially bigger headache down the road. Nothing beats getting advice from someone who's been through the same thing!