How to Clean Carbon Deposits Inside the Engine?

[DiJourney]

Remove the engine intake manifold, scrape off stubborn carbon deposits, clean thoroughly, and reassemble. Below are relevant details about the engine: 1. Precautions: Using a blowtorch to heat the oil pan in winter may cause oil congealing and pan deformation, increasing fire risks. 2. Common Issues: Cold-start engine vibration. The engine idles roughly during cold starts but returns to normal after warming up. The primary cause is excessive carbon buildup inside the engine. During cold starts, fuel injected by the injectors gets largely absorbed by carbon deposits, resulting in an overly lean air-fuel mixture that makes ignition difficult. Only after the deposits become saturated with fuel does the engine start easily. Once running, the fuel adsorbed on the carbon deposits re-enters the combustion chamber, enriching the mixture. This fluctuation between lean and rich mixtures causes rough idling after cold starts. Another potential cause is misfiring, often due to faulty spark plugs or ignition coils. Cleaning cylinder carbon deposits or replacing these components can resolve the issue.