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LucRedstar

Problems with BMW 5 Series (2009): Black smoke, high fuel consumption and uneven engine running

Poor fuel economy

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Car won't start

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Black smoke from exhaust on acceleration

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Jerking on acceleration

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Stalling while idling

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Shaking while idling

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Loss of engine power

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Unsteady engine

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Check engine light on

Hi, I have a problem with my 2009 BMW 5 Series. The car emits black smoke when accelerating, the engine light comes on and the performance decreases. I also notice a jerking when accelerating and the engine runs unevenly. Sometimes it won't start at all and the fuel consumption is also higher than normal. When stationary, it occasionally stalls and shakes when the engine is idling. I have come up with the idea that it may be due to a defective ignition coil or misfiring. Do any of you here have experience with such symptoms? What has your garage done in such a case and how did you solve it? I look forward to your feedback and tips. Thanks in advance!

(Translated from German)

6 comment(s)


TomBerg

Hi, I had a similar situation with my 2007 BMW 3 Series. So, I have some experience, but I'm not an expert. Anyway, my garage replaced the engine control unit because it was faulty. This cost me 1000 euros, quite a large sum, but it solved the problem. But I would like to know more about your car to be able to help you better. Have you been able to identify any fault codes? What is your usual maintenance schedule? The information may help to better isolate the problem. VG

(Translated from German)

LucRedstar (Author)

Hello, thanks for the quick reply! I haven't actually determined an error code as I don't have the tools to do so. My last inspection was about 15,000 km ago, so at 139,712 km, and my mechanic didn't find any problems then. So maybe the problem lies deeper and is not visible at first glance... Or as you said, it could be the engine control unit, hopefully it's not that, that sounds like pretty expensive damage. Maybe someone else here can share their experience. VG

(Translated from German)

TomBerg

Hi again, thanks for the additional info. So, based on your symptoms and the fact that you don't have a fault code, it could also be due to the fuel supply. Lack of fuel pressure or dirty fuel jets could be causing the problems you describe. Perhaps they were overlooked during the last inspection. Of course, this is only one possibility. Some part of the exhaust system could also be damaged, or maybe even the turbo. And yes, it could also be the engine control unit, but better to narrow down the fault before jumping to the most expensive part. It would be wise to get a diagnostic tool or someone who has one. It might help you see what exactly the problem is before you spend a lot of money. Stay tuned and keep us posted. Good luck with your sorting! VG

(Translated from German)

LucRedstar (Author)

Hello, thank you for the new information. A problem with the fuel supply or the fuel jets sounds plausible. I'll try to get a diagnostic tool and go looking for the cause before I venture into the more expensive repair options. I will definitely report back when I have any news! Thanks for the tips and your time! VG

(Translated from German)

CarFreak

Good day, I am seeking advice on my 2013 BMW 3 Series with 132,500 km. I'm experiencing black smoke, high fuel consumption, and uneven engine running. What could be causing these issues, and how can I fix them? Any insights or recommendations for diagnostic checks and potential repairs would be appreciated. Thanks!

CarlyMechanic

@CarFreak

Good day, I am seeking advice on my 2013 BMW 3 Series with 132,500 km. I'm experiencing black smoke, high fuel consumption, and uneven engine running. What could be causing these issues, and how can I fix them? Any insights or recommendations for diagnostic checks and potential repairs would be appreciated. Thanks!

Based on your symptoms, it could be a problem with your fuel injectors or air filter. Start by checking your air filter to ensure it's clean and not obstructing airflow. If it's dirty, replace it. If the problem persists, you may need to have your fuel injectors inspected for leaks or blockages. If these checks don't resolve the issue, I recommend taking your car to a mechanic for a thorough inspection, as these symptoms could also indicate more serious issues like a failing turbocharger or a problem with the engine control unit.

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