BMW 318d Rough Running & Power Loss, Intake Fix Needed

I had the exact same symptoms on my BMW 320d (2015) last year. The rough idle, power loss, and that distinctive hissing noise, totally matches what I experienced. Got it diagnosed and yes, it was the intake manifold control switch that went bad. Had it fixed at my local garage and they needed to replace the entire manifold assembly because the actuator was faulty. It took them about 4 hours to complete the job. It's actually a common issue with these engines and definitely not something you want to ignore, it can lead to more serious engine problems if left unchecked. The symptoms you're describing are pretty much textbook for a failed intake manifold flap control. My advice would be to get it checked soon, as driving with this issue can potentially damage other engine components. The increased fuel consumption you're noticing is also typical with this problem. Just make sure whoever works on it has experience with BMW diesels, it's not the most complicated repair, but it needs to be done right.

Thanks for sharing your experience! It really helps to hear from someone who went through the same thing. I ended up getting mine fixed too and it definitely made a huge difference in how the car runs. Just curious, do you remember roughly how much you paid for the repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up?

Hey there! Glad to hear you got it sorted out! Yeah, I remember my repair costs clearly, it came to 465 € for replacing the faulty intake manifold control switch. Since getting it fixed, my 320d has been running like a dream, no more hissing sounds, power loss, or any of those annoying symptoms. The fuel economy is back to normal too, which is a massive relief for my wallet! It's been over a year now since the repair, and I haven't had a single issue related to the intake manifold. The car feels just as responsive as it did when I first got it. Honestly, it was worth every penny to get it properly fixed rather than letting it get worse. These BMWs are solid cars when you take care of problems quickly. Just keep up with regular maintenance, and you shouldn't see this problem come back. How's your car feeling now after the repair? Bet it's like driving a different machine!

Thanks! Yeah, my repair ended up being pretty similar in cost. The mechanic I finally went with was great, really knew his stuff. After getting it fixed, it's like I'm driving a completely different car! No more hissing, the power's back, and I'm not burning through fuel like before. Funny story actually, when I first took it in, I was super nervous because of my bad experience with the previous mechanic. But this new guy walked me through everything, showed me the faulty parts, and explained what he was going to do. He even had it done faster than expected, took about 3 hours. The best part? I took it for a long drive right after, and it was smooth sailing all the way. You're absolutely right about taking care of these issues quickly, lesson learned! Really appreciate you sharing your experience. It definitely helped me feel more confident about getting it sorted properly.