BMW X5 Rough Idle Mystery: IAC Valve or Something Else?

Hey there! Had the exact same symptoms on my 2018 BMW X4 last year. It wasn't the idle air control valve in my case, turned out to be severe carbon buildup in the intake manifold and valves. These direct injection engines are prone to this issue. Took it to the garage and they had to do a complete intake cleaning service. They showed me the before and after, the carbon deposits were pretty bad. It was definitely a serious problem that needed immediate attention, as it can lead to more expensive repairs if left unchecked. After the cleaning, the rough idle and stalling completely disappeared, and the engine ran smooth again. The check engine light also went off. Been running great since then, but I now use high-quality fuel and do more regular maintenance to prevent buildup. My advice would be to get it checked specifically for carbon buildup before replacing any parts. The symptoms are really similar to a faulty idle control valve, but in these engines, it's more commonly the intake contamination issue. Hope this helps.

Thanks so much for sharing that, really helpful info! Carbon buildup makes total sense with these symptoms. Would you mind telling me what the cleaning service ended up costing you? Also curious if you've had any issues pop up since the cleaning was done? My X5 is my daily driver so I need to get this sorted quick.

Hey again! Just following up, I actually visited my mechanic last week and it turned out you were spot on with your suggestion about the carbon buildup! Fixed the bad idle control valve and got the heavily contaminated intake all cleaned up. The whole job came to 425 €, money well spent considering how much better the car runs now. Since the cleaning, it's been running like a dream, no more rough idling or stalling issues whatsoever. It's amazing what a difference proper maintenance makes! The engine feels much more responsive, and that annoying check engine light is finally gone. If you're using yours as a daily driver like I do with my X4, I'd definitely recommend getting it looked at sooner rather than later. The peace of mind alone is worth it. Plus, waiting too long could lead to more expensive problems down the road. Make sure to keep using good quality fuel going forward, I've been doing that since my repair and it seems to help keep things running smoothly. Let me know how it goes with yours!

Thanks for the follow-up! Just got back from my mechanic visit today, and what a relief, the car's running perfectly now! The carbon buildup was pretty severe, but they did a thorough cleaning job. Cost me around 400 for everything, which honestly feels like a bargain considering how much better it runs. No more embarrassing stalling at traffic stops! The engine's running super smooth, and that annoying check engine light is finally off. My mechanic was great too, showed me all the gunk they cleaned out and explained how to prevent it from building up again. Thanks again for pointing me in the right direction with the carbon buildup suggestion. You saved me from probably replacing parts that weren't even the problem. I've already switched to premium fuel, and I'm planning to stick to a proper maintenance schedule from now on. Really appreciate everyone's help with this, nice to know I wasn't alone dealing with this issue!

I would like to know if with Carly I could increase or decrease the idle speed of my BMW x5 e70 35i year 2012? Thanks

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I want to increase the idle RPM of my BMW x5 e70 35i year 2012.

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Hello, our Carly support team is here to help you. Please contact us by clicking on this link and we will get back to you shortly. https://support.mycarly.com/hc/es/requests/new?ticket_form_id=360000444960

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