How to Clean Thick Sludge Inside the Engine?
3 Answers
The method to clean thick sludge inside the engine is: 1. Drain the oil from the oil pan while the engine is hot, and reinstall the plug after the oil has completely drained; 2. Add light diesel oil (equal in quantity to the engine oil) into the crankcase; 3. Start the engine and let it idle for about 3 to 5 minutes before shutting it off; 4. Immediately drain the diesel oil from the oil pan (the diesel oil will have turned into dirtier and blacker residue than the original engine oil); 5. Add new engine oil, drive for about 20 kilometers, and then change the oil again. An engine is a machine that converts other forms of energy into mechanical energy, including internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, and electric motors.
I've dealt with thick engine sludge before, especially when doing DIY cleaning. I prefer using specialized engine flush additives. First, start the engine and warm it up for ten minutes, then pour the cleaner into the old oil and let it idle for 15-20 minutes to circulate and dissolve sludge internally. After that, turn off the engine, drain the old oil and residue, and replace it with fresh oil and a new filter. The process is simple but effective—after cleaning, the engine runs smoother with less noise. If sludge blocks oil passages, it can lead to insufficient lubrication, component wear, or even overheating damage. I recommend using branded cleaners to avoid damaging seals, paired with high-quality synthetic oil to prevent buildup. Avoid frequent short trips and delayed oil changes—this long-term maintenance can save significant repair costs.
In our frequent handling of such repairs, the most commonly used method for cleaning engine sludge is professional chemical cleaning. First, connect a circulation device to the oil filler port and inject a solvent, then let the engine run for about ten minutes to dissolve the deposits. In severe cases of sludge buildup, it may be necessary to disassemble the engine for manual cleaning or replace certain components. Customers report that after cleaning, they experience restored power and reduced fuel consumption, feeling it's well worth it. For prevention, it's recommended to perform maintenance every 8,000 kilometers using full synthetic oil to keep the oil passages clear. Neglecting sludge buildup can increase friction, affect performance, and even lead to cylinder scoring risks. Additionally, avoiding prolonged low-speed idling can help extend oil life.
