The directions for Berryman Oil Change Flush all for adding one 16-oz bottle of product to 3-6 quarts of engine oil immediately before an oil and filter change. Start the engine and allow it to idle until the oil is at operating temperature. (Since you’re trying to address a known issue, you might wait as long as 15-20 minutes.) Turn off the ignition and allow oil to cool sufficiently for safe handling. Drain and replace engine oil and filter.