Black smoke and loss of power in Renault Laguna 2005: Possible boost pressure system malfunction?

Hi, I had similar problems with my 2008 Renault Mégane. Mine actually had mechanical damage to the turbocharger, just as you suspected. The symptoms were similar to those you described. There were loud hissing noises when accelerating, irregular acceleration, loss of power and the engine light also came on. This is definitely a serious issue because the turbocharger is putting a lot of stress on your engine. After the diagnostic appointment at the workshop, they then had to completely replace the turbocharger. Neither a repair nor a cleaning would have solved the problem. The car is now running smoothly again. So my tip for you: make sure you get it repaired as soon as possible! I hope this helps you.

(Translated from German)

Hey, thanks for your quick reply! That sounds like exactly what I was afraid of. Do you happen to remember how much it cost you to have the turbocharger replaced? And have there been any other problems or similar incidents with your Mégane since then? Your experience really helps me, so thanks again!

(Translated from German)

Hi, I'm glad my experience has helped you. The whole thing cost me €1070. It wasn't cheap, but since the mechanic fixed the malfunction in the boost pressure system, my Mégane drives like a dream again. No further problems or similar incidents have occurred since the repair. Hope you get your problem under control soon. All the best!

(Translated from German)

Thanks for the information! That's a lot of money, but considering that the car will run smoothly again afterwards, it sounds like a worthwhile investment. I guess I won't be able to avoid an appointment with the mechanic then. I hope I have the same luck as you and that my Laguna doesn't start acting up afterwards. Thanks again for your valuable input. I now have a better idea of what to expect. Take care!

(Translated from German)