In simple terms, decarbonizing an engine involves removal of carbon deposits from the engine, using either mechanical (physical) or chemical methods. The procedure of mechanically cleaning out carbon deposits entails removal of the cylinder head and then, physically scraping off carbon deposits from the top of the pistons, the combustion chamber and other components.
Oil additives are vital for the proper lubrication and prolonged use of motor oil in modern internal combustion engines. Without many of these, the oil would become contaminated, break down, leak out, or not properly protect engine parts at all operating temperatures. Just as important are additives for oils used inside gearboxes, automatic transmissions, and bearings. Some of the most important additives include those used for viscosity and lubricity, contaminant control, for the control of chemical breakdown, and for seal conditioning. Some additives permit lubricants to perform better under severe conditions, such as extreme pressures and temperatures and high levels of contamination.
Oil flushing is the process of flushing out the oils, Oil sludge or black sludge. This is a solid or gel in motor oil caused by the oil gelling or solidifying, usually at temperatures higher than 100 degrees Celsius. Oil sludge can be a major contributor to internal combustion engine problems and can require the engine to be replaced, if the damage is severe.