If you are looking for an engine flush that will be compatible … Add Pro-Line Engine Flush to the engine oil at operating temperature before changing the oil. Liqui Moly 2037 Pro-Line Engine Flush. 10 minutes. One 300 ml can is sufficient for up to 6 liters of oil. Then change the oil and the filter. Pro-Line Engine Flush is compatible with most commercially available engine oils, and in oil running belt. Liqui Moly proves that flushing your engine doesn’t have to be a headache—simply pour the 2037 Pro-Line engine flush into your warm engine and let … Add Engine Flush to the motor oil at running temperature before changing the oil. Engine Flush is compatible with all commercially available motor oils. After adding the product allow the engine to idle for 10 to 15 minutes depending on the degree of contamination. After adding the product, allow the engine to idle for approx. Then change the oil and the filter.