Mitsubishi Shumma Engine Conditioner is the No. 1 Japanese deagglomeration engine, according to most professional craftsmen and experienced drivers. Mitsubishi's Noise Milling is an oil-based solvent, 20% composed of ethylene glycol and monoethyl ether, it smells like ammonia and is representative of hard coal removal. This cleaner is an active foam designed to clean GDI engines (direct injection), but actually removes soot in any engine. Injected into the cylinders through the tube. It is stored for 30 minutes, but according to the recommendation it is most effective when exposed to 3 to 5 hours. Valve packing is not aggressive.

One cylinder is enough to decorate a 1.5 liter engine. Baking powder copes with soot on pistons, rings, valves and combustion chamber. It can be used not only without disassembling the engine, but you can also soak the parts of the piston group to remove sludge.
And if its application did not produce results, then we can say with certainty that only repair can already help.