This product combines solvents and surfactants in a water-free formula that is highly penetrant and extremely efficient at reaching all the nooks and crevices of the engine. Apply only to an engine that is off and cool. To prevent any damage or short-circuit, cover all electrical parts, sensors, wiring, intakes and other sensitive areas. Shake well and spray generously on a dry engine focusing on the sections with the deepest deposits. Rinse over spray from the bodywork and other painted parts to prevent damage to the paint or wax. Allow product to act for 10-15 mins, brush away deposits that may require additional help. This product is water-free, so it must be rinsed with running water. Rinse the engine from top to bottom with a low flow of water. The product will react when in contact with the water, turning white. Once rinsing is done and the engine has dried, remove all covers and reinstall any part that was removed.