Drive down to your local Self serve wand car wash. Turn knob to tire/engine cleaner. spray engine making sure you get around the front, sides and as much of the oil pan you can. let soak a few minutes. Turn knob to Rinse and Mist the engine in clean water. spraying the wheel wells and fire wall.If you still have a lot of build up you can use the high pressure of the "rinse" to hold the wand close and blast it off.