Oil sludge
Oil sludge or black sludge is a gel-like or semi-solid deposit inside an internal combustion engine, that can create a catastrophic buildup. It is an emulsion of engine oil soluble combustion productions, water and solids. Particles accumulating in the sludge, can cause excessive engine wear. The sludge can also block the oil pump inlet screen or oil channels, causing oil starvation.
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