BMW 2 Series Rough Running + Hissing: Air Leak Alert

Hey there! I actually dealt with similar issues on my 2016 BMW 3 Series last month. The symptoms were pretty much identical to what you're describing, the hissing, rough acceleration, and CEL. Turned out my intake boot had several small cracks, causing an air leak. The mechanic showed me how the rubber had deteriorated over time, which is quite common in these engines. Also found the clamps were a bit loose, making the leak worse. Got it fixed with a new intake boot and proper clamp installation. While it wasn't a major repair, leaving it unfixed could've led to bigger problems since the engine wasn't getting the right air-fuel mixture. I'd definitely recommend getting it checked sooner rather than later. The repair itself wasn't complex, just needed the right parts and about an hour of labor. The car's been running smooth since then, much better throttle response and no more hissing. Best of luck with yours!

Hey, thanks for sharing your experience! That's really helpful since it sounds exactly like what I'm dealing with. Your insight about the intake boot makes a lot of sense. Would you mind sharing how much you ended up paying for the fix? Also, curious to know if you've had any other issues pop up since the repair? Thanks again for the detailed response!

Hey again! Just to update you, I went ahead and had my car fixed at the mechanic after sharing my initial experience with you. The total cost was 100 € for fixing the intake hose leak, which was actually less than I expected! Since getting it repaired, my car's been running like new, no more hissing sounds, rough acceleration is gone, and the engine's performing perfectly. I can honestly say I haven't had a single issue pop up since the repair last month. The throttle response is crisp, and the engine's running super smooth. It's such a relief to have that sorted out. The mechanic did a great job explaining everything, and now I understand why those rubber parts can wear out over time. My advice would definitely be to get it checked out soon, the peace of mind is totally worth it, and the fix is relatively straightforward and affordable. Let me know how it goes with yours!

Thanks for the follow-up! I actually bit the bullet and took my car to a different mechanic yesterday. You were spot on, it was the intake boot causing all the trouble. Got charged 120 € for parts and labor, which wasn't too bad considering how much better the car runs now. The mechanic walked me through the whole thing, showed me the cracked boot, and explained how these issues develop. Pretty interesting to actually see the damaged part! The repair took about an hour and a half, and wow, what a difference. The car feels completely different, no more hissing, smooth acceleration, and the check engine light's finally off. Really glad I didn't put this off any longer. Feels good to have a properly running car again. Thanks for giving me the confidence to get it sorted out, your advice was super helpful!