BMW 5 Series Rough Idle & Stalling, IAC Valve Issue?

Hey there! Some experience with BMWs here. Had a really similar issue with my 2001 BMW 3 Series (also gas engine). Same symptoms, rough idle, stalling, and that annoying check engine light. Turned out the intake was heavily contaminated, causing all sorts of problems with air flow. Took it to my regular workshop and they did a thorough intake cleaning service. Bill came to 425 Euro, but it fixed the problem completely. Engine's been running smooth since then. Before suggesting anything specific for your case, could you share: Current mileage? When was the last time you had any engine cleaning service done? Any other symptoms besides the rough idle and stalling? Let me know these details and I might be able to help more specifically!

Thanks for the detailed response! Currently at 153294 KM and just had my regular service last month. Actually, I'm also noticing slight hesitation during acceleration and the engine seems to run a bit rougher when the A/C is on. Your intake cleaning suggestion sounds promising, been dealing with this for about 2 weeks now and getting pretty tired of the unusual stalling. Going to check with my mechanic about doing a thorough intake cleaning. The symptoms you described with your 3 Series sound exactly like what I'm experiencing.

Hey again! Yeah, those extra symptoms you mentioned, especially the hesitation during acceleration and the rough running with A/C, that's exactly what I experienced with my 3 Series. The more you describe it, the more convinced I am it's the same issue I had. The intake cleaning really worked wonders for me. Just want to mention though, mine started showing these symptoms around 160,000 KM, pretty close to where you're at. One thing I learned is that it's worth getting the intake cleaned before it gets too bad. When I waited too long, it just made the symptoms worse. Quick tip from my experience, while they're doing the cleaning, might be worth having them check the MAF sensor too. When they cleaned mine, they noticed the MAF sensor was pretty dirty as well, and cleaning that helped with the overall performance. Been about 8 months since I had mine done and haven't had any issues since. Running smooth as butter now, even with the A/C on full blast. Let me know how it goes after you get it checked out!

Thanks so much for the additional info and tips! Really appreciate you sharing your experience, especially about the MAF sensor. Makes total sense to get that checked while they're in there doing the intake cleaning. I've already called my mechanic and scheduled it for next week, they actually mentioned they see this issue quite often with these engines at this mileage range. Kind of relieved to hear your car's been running great for 8 months after the cleaning. Getting tired of that anxiety every time I stop at lights, wondering if the engine's going to stall! Will definitely update you once I get it back from the shop. Hoping for the same smooth-running results you got with yours. Really thanks again for taking the time to help out. Having someone who's been through the exact same thing makes me feel much more confident about getting this sorted!