What are the symptoms of excessive engine carbon buildup?

[VonBrooklyn]

Engine carbon buildup can manifest in several ways: 1. Engine vibration, where the engine exhibits intermittent and rhythmic shaking under idle conditions; 2. Unstable engine idle, where the engine's RPM fluctuates unpredictably during idle; 3. Poor acceleration, as severe carbon buildup can lead to sluggish or weak acceleration, often accompanied by abnormal engine vibrations and increased fuel consumption; 4. Engine knocking, where excessive carbon deposits in the combustion chamber increase the engine's compression ratio, causing premature combustion of the air-fuel mixture and resulting in detonation; 5. Cylinder scoring, which occurs when carbon deposits accumulate near the piston rings or when carbon from the cylinder head or valves falls onto the piston rings, potentially leading to severe engine damage or even cylinder seizure in extreme cases.