1. Use a chemical engine cleaner. There are a number of commercial engine cleaners available that can help to dissolve sludge. Follow the directions on the product label carefully.
2. Make your own engine cleaner. You can also make your own engine cleaner by mixing equal parts of acetone, kerosene, and automatic transmission fluid. Pour the mixture into the engine and let it sit for 30 minutes to an hour. Then, drain the mixture and change the oil filter.
3. Use a high-pressure water sprayer. Another way to remove sludge from an engine is to use a high-pressure water sprayer. Be careful not to spray water directly at the electrical components of the engine.
4. Take the engine apart and clean it manually. If the sludge is very bad, you may need to take the engine apart and clean it manually. This is a time-consuming and labor-intensive process, but it is the most effective way to remove all of the sludge.
Once you have removed the sludge from the engine, it is important to change the oil and filter. You should also flush the cooling system and replace the coolant. This will help to prevent the sludge from coming back.
