BMW X4 Stalling Mystery: Secondary Air Pump Gone Wild

Had the same issue with my 2011 BMW X3 last year. The symptoms were identical, engine stalling, jerking, and that annoying secondary air pump behavior. Turned out the connection hose from the pump to the air valve was damaged, had some cracks and wasn't sealing properly. This caused inconsistent air flow and triggered the check engine light. My mechanic found it during a pressure test. It's not a catastrophic problem if fixed promptly, but leaving it unchecked can lead to bigger issues with the emission system and engine performance. The repair involved replacing the hose assembly and checking the valve function. The funny thing is, I initially thought it was something more serious with the engine control unit. If your symptoms match mine, get that hose connection checked first. A good mechanic should be able to diagnose it with a proper pressure test.

Hey there! That's really helpful info about the hose issue. I'm having pretty much the exact same trouble with my X4 right now. Mind if I ask how much you ended up paying for the fix? Also, has everything been running smoothly since the repair, or have you noticed any other problems pop up? Just want to get an idea of what I might be looking at cost-wise and if this fix actually solves it for good.

Hey again! Glad I could help point you in the right direction. I just got my car back from the shop last week actually, they fixed that pesky air valve issue and it cost me 175€ for the whole job. They found exactly what I suspected, the hose connection from the pump to the valve was shot. The car's running like a dream now! No more jerking, no stalling, and that annoying check engine light is finally off. The secondary air pump's working perfectly too, kicks in normally when it should and stops when it should. Such a relief after all that hassle! Honestly, I was worried it might be something way more expensive, so I'm pretty happy with how it turned out. It's been about a week since the fix, and I've put some decent miles on it without any problems. If your symptoms are matching what I had, you're probably looking at a similar repair cost. Just make sure they do a proper pressure test to confirm it's the same issue. Trust me, getting it fixed properly is worth every penny, no more stress every time you start the car wondering if it's going to act up!

Thanks a lot for sharing your repair experience! I finally got my X4 checked out yesterday, and you were spot on. Had the same hose problem, though my repair came in a bit higher at 220€. Still, way better than what I was fearing it might cost! It's such a relief to drive without that constant worry now. No more unusual stalling or jerking, and the engine's running super smooth. Even took it on a longer drive today just to make sure everything's good. Best part? That annoying check engine light is finally gone! The mechanic I found did a fantastic job, way better than my last one. They showed me the damaged hose and explained everything clearly. Really glad I asked here and got your advice about the pressure test, saved me from probably getting unnecessary expensive repairs done. Thanks again for helping me sort this out. Sometimes these car issues seem huge until you find someone who's dealt with the same thing!