Viano gasoline engine knocking and power loss

I understand your frustration I have experienced similar symptoms with my Mercedes Vito, although I must clarify that I have not confirmed the build year to be the same The reduced engine power, jerking during acceleration, and presence of smoke suggest a potential issue related to the combustion process The knocking sound you describe could indeed be engine knock, possibly stemming from pre-ignition This can be caused by deposits within the combustion chamber altering the ignition timing and creating hot spots Have you investigated the condition of your cylinder heads

Cylinder heads, huh Honestly, I haven't a clue about cylinder heads Are they easy to check myself, or am I better off just taking it to a mechanic And what kind of deposits are we talking about Could it be something I could try to clean out myself with some fuel additive or something

While a visual inspection of the cylinder heads might offer some insight, a proper diagnosis would likely require specialized tools and expertise to assess the combustion chamber and valve condition accurately Regarding the deposits, these typically consist of carbon buildup resulting from incomplete combustion Although fuel additives may offer some cleaning action, their effectiveness in resolving significant pre-ignition issues can be limited Considering the symptoms you've described, including the error code and reduced power, I would strongly recommend consulting a qualified workshop to perform a thorough diagnostic assessment It may prevent further damage

Thanks for the advice I took it to a local shop, and they confirmed it was carbon deposits in the combustion chamber causing pre-ignition, just like you suspected They did a combustion chamber cleaning, and it cost me about 425€, but now it runs like a champ again No more knocking, power is back, and no more smoke Really appreciate your help