Vauxhall Adam's Power Loss: Cylinder Knock Crisis?

Hey there! I've got some experience with this kind of issue. Had something very similar with my 2017 Vauxhall Corsa last year. From what you're describing, it sounds just like what I went through. I dealt with identical symptoms, rough running, power loss, and that annoying engine noise. Turned out to be carbon deposits in the combustion chamber. Took it to my trusted mechanic who did a thorough cleaning of the chambers and replaced some related parts. Cost me around 425€, but it sorted everything out completely. What fuel grade are you usually using? Also, how many miles has your Adam done? This info would help me give you more specific advice based on my experience. (Experience level: Some experience with basic car maintenance and common issues)

Thanks for sharing your experience! My Adam's at 68962 KM and had its last service about 3 months ago. I've been using regular 95 octane fuel from Shell mostly. Interesting that you mention carbon deposits, that could explain a lot. Were there any warning signs before your issues got bad? Just trying to figure out if I should've caught this earlier. I'll definitely get it checked out by a mechanic ASAP before it gets worse. I'm a bit worried about the cost though, 425€ is quite a bit! Was that just for the cleaning, or did they have to replace other parts too?

Hey again! Yeah, thinking back to my Corsa's issues, there were definitely some early warning signs I probably should've paid more attention to. Started with slightly reduced fuel efficiency, nothing major at first, just noticed I was filling up a bit more often. Then came occasional hesitation during acceleration, especially on cold mornings. The 425€ breakdown was roughly 180€ for the carbon cleaning service, and the rest went to replacing the spark plugs and one faulty fuel injector that was contributing to the problem. My mechanic said the carbon buildup had actually damaged the injector over time, that's what really drove up the cost. If you catch it early enough, you might just need the cleaning service. Actually, using 95 octane from Shell is exactly what I was using too! My mechanic suggested switching to higher octane fuel (98) and adding a fuel system cleaner every few months. Been doing that since the repair and haven't had any issues for almost a year now. One tip though, if you're hearing that knocking sound, don't wait too long to get it sorted. I learned the hard way that these issues tend to get more expensive the longer you leave them. Better to tackle it now than end up with more damaged parts like I did!

That's really helpful info, thanks! You've definitely convinced me to get this sorted quickly, don't want to end up with a damaged injector on top of everything else. I'll book it in with my mechanic tomorrow and mention the carbon deposit issue. Good shout about switching to 98 octane fuel too, I didn't realize it could make such a difference. I think I did notice the fuel efficiency dropping a while back but just put it down to winter weather. Guess that was probably an early warning sign I missed. Oh well, live and learn! At least now I know what to watch out for in the future. Thanks again for all the advice, really appreciate you taking the time to share your experience!