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Thorstheim

VW Passat 2008: Black smoke emissions and high fuel consumption

Black smoke from exhaust on acceleration

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Jerking on acceleration

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Loss of engine power

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Unsteady engine

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Poor fuel economy

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Check engine light on

Hello everyone, I am having trouble with my 2008 VW Passat. It is emitting black smoke from the exhaust when accelerating, the check engine light is on and it is showing signs of loss of engine power and irregular engine running. It also jerks when accelerating and fuel consumption is high. I think it may be due to the lambda sensor heater, which heats the sensor to quickly reach operating temperature and accurately measure exhaust emissions. Have any of you ever had a similar problem and know the best way to solve it? I'm looking for tips and experiences to better isolate and understand the problem, especially how you fixed it in the workshop. Looking forward to your advice. Thank you very much!

(Translated from German)

4 comment(s)


KurtMesser

Hello, I had a similar problem with my VW Golf 2006, so almost the same situation. I'm not a mechanic, but in my case the problem was a faulty engine control unit, which apparently only happens very rarely. I had it repaired at my garage and it cost around 1100 euros. At the time it was a pretty slick place to go, they spotted the fault and fixed it immediately. I remember very clearly that the engine ran better afterwards and the fuel consumption normalized. Can you give me some more information about your Passat? Then I might be able to help more specifically, perhaps someone else has had similar experiences with the specific model. Hope that helps a bit!

(Translated from German)

Thorstheim (Author)

Thank you very much for your answer and tips. Well, my Passat has about 124852 km on it. I've also had a problem with the exhaust system before. However, it is really strange that the engine control unit of all things could be defective. As far as I know, they are normally very robust and durable. Did you notice any other symptoms before you discovered the problem with the engine control unit that were similar to my Passat? I hope I can narrow down the problem and find a solution before it gets any worse. Thanks in advance!

(Translated from German)

KurtMesser

Hello again! It's really strange that you're having such difficulties. I actually had some similar symptoms before the engine control unit was replaced. Just like you, there was the dark smoke and the car jerked when accelerating. But the clearest indication, in my opinion, was the check engine light coming on. That's when I realized that something was definitely wrong! I also had over 120,000 kilometers on the clock at the time and the mechanics said that this can happen with such a mileage. Fortunately, I didn't have any major damage. Replacing the engine control unit really worked wonders. So my advice to you would be to have it checked by a specialist workshop ;) I hope this helps you and keep my fingers crossed that you find a solution quickly!

(Translated from German)

Thorstheim (Author)

Hi again, thanks for taking the time to share more! That's interesting and seems pretty close to what I'm experiencing. Would you have any advice on which garage I could contact or how I could avoid such problems in the future? I'm really grateful for your support and look forward to your further response!

(Translated from German)

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