Petrol-powered Mercedes Citan 2012: rough engine running, loud whistling sound and black smoke

Hi buddy, first let me say I feel you, had similar issues with my 2015 Mercedes Citan. You don't experience mechanical damage to the turbocharger just like that. I had similar symptoms, especially the whistling and black smoke. When I took the car to the garage, they were quite serious and said it was the turbocharger. So with the symptoms described, I would be careful and not take the problem lightly. Imagine, the turbocharger can even break down in such a way that it damages the engine. Fortunately, I was able to avoid this during my last visit to the workshop. So, in my experience, take it to the workshop. I wouldn't dare to repair something like that myself. I hope this helps you a little. Cheers

(Translated from German)

Hi, thanks for the advice, I'd better visit a workshop quickly. The turbocharger seems to be a real sticking point... Do you happen to remember how much the repair cost you in the end? And have you had any other problems with the Citan since then? Regards

(Translated from German)

Hi Ingewag, great that you acted so quickly! Fortunately, I have to say that everything is fine with my Citan since my last visit to the mechanic. They were able to fix the malfunction in the boost pressure system. As for the cost... well, it did hurt a bit. The repair of the mechanical damage to the turbocharger cost around €1070. But what can you do when it's your favorite car, right? So far everything is going smoothly, toitoitoi. Regards

(Translated from German)

Hi Anna, wow, that's a tidy sum! But you're right, it's better to have something like this repaired before it gets any worse. And the car really is a treasure. I'm glad to hear that your Citan has been running well since then. That gives me a little hope. So I'm going to call my garage right now and hopefully it's not too bad. Thank you for the helpful advice and your experience. Regards

(Translated from German)

Hello everyone, I'm worried about my Mercedes GLC 250; year of manufacture 2018; petrol engine; 130,000 km. It hasn't accelerated properly for 2 months. My mechanic around the corner couldn't tell me what the problem is because his readout device didn't show anything. Now I have had my car read out with the Carly app and lo and behold "the boost pressure of turbocharger 1 is too low". Unfortunately, I don't know exactly what the cause is. Up to a speed of approx. 100kmh the car doesn't cause any problems. But as soon as I am on the highway and want to accelerate a little faster, the car automatically shifts 3-4 gears (from 7th or 8th to 4th or 5th gear). If I then briefly take my foot off the accelerator, it shifts up again and I can maintain the speed at around 140-150 kmh. But as soon as I step on the gas again, it shifts back into 4th or 5th gear. I could not detect any hissing or black smoke. Has anyone had the same experience?

(Translated from German)

Hi Lujo17, the issue you're describing could be due to a leak in the turbocharger system, a faulty turbocharger, or a problem with the wastegate control. I would recommend starting with a visual inspection of the turbocharger system for any obvious leaks or damage. If you don't find anything, you might need to have a mechanic perform a more detailed inspection. This could include checking the wastegate control and the turbocharger itself. Please keep us updated on your progress. Do you have any other questions?