Oil sludge is a solid or gel-like substance composed of hydrocarbons, water, and inorganic materials that can form inside an engine during normal operation. The main causes of oil sludge are:
1) Poor quality oil: Using lower quality oils can cause increased deposits of impurities, which can lead to sludge formation.
2) Lack of maintenance: Not changing your oil regularly or not using the correct type of oil for your engine can also lead to sludge formation.
3) Excessive heat: Operating your engine at high temperatures for extended periods of time can break down the oil and create sludge.
4) Water contamination: Water contamination can also cause oil to break down and form sludge.