Tucson Hybrid engine knocking and smoke

That sounds rough! Engine knocking, especially in a hybrid, can be tricky. The jerking and smoke are red flags. Considering the mileage, have you ever had the combustion chamber cleaned? Deposits in the combustion chamber can build up over time and cause issues, like pre-ignition, changing the ignition timing and leading to the knocking you're hearing. Is it worse when the engine is cold?

Thanks for the quick reply! I haven't specifically had the combustion chamber cleaned. The car has had regular servicing, but I'm not sure if that's something they automatically do. And yes, it does seem worse when the engine is cold. If it is carbon deposits, is there anything I can do myself, or am I looking at a mechanic visit?

Given that it’s worse when cold and you're getting those symptoms plus an error code, carbon deposits causing pre-ignition or knock is likely. While there are DIY combustion chamber cleaning kits out there, I'd honestly recommend taking it to a reputable mechanic. They can properly diagnose the issue, check for any damage, and thoroughly clean the combustion chamber. Messing with ignition timing isn't something you want to risk if you're not experienced.

Okay, that makes sense. I'll book it in with a local mechanic then. I got the repair bill, they found and cleaned bad deposits in the combustion chamber. Cost me 425€, but she's running smooth again. Thanks for confirming what I suspected and giving me the push to get it sorted!